RECORD: Darwin, C. R. ed. 1839. Mammalia Part 2 of The zoology of the voyage of HMS Beagle. by George R. Waterhouse. Edited and superintended by Charles Darwin. London: Smith Elder and Co.

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THE object of the present Introduction, is briefly to describe the
principal localities, from which the Zoological specimens, collected
during the voyage of the Beagle, were obtained. At the conclusion of
this work, after each species has been separately examined and
described, it will be more advantageous to incorporate any general
remarks. The Beagle was employed for nearly five years out of England;
of this time a very large proportion was spent in surveying the coasts
of the Southern part of South America, and of the remainder, much was
consumed in making long passages during her circumnavigation of the
globe. Hence nearly the entire collection, especially of the animals
belonging to the higher orders, was procured from this continent; to
which, however, must be added the Galapagos Archipelago, a group of
islands in the Pacific, but not far distant from the American coast.
The localities may be briefly described under the following heads.

BRAZIL. This country presents an enormous area, supporting the most
luxuriant productions of the intertropical regions. It is composed of
primary formations, and may be considered as being hilly rather than
mountainous. LA PLATA includes the several provinces bordering that
great river;—namely, Buenos Ayres, Banda Oriental, Santa Fé, Entre
Rios, &c. My collections were chiefly made at BUENOS AYRES, at
MONTE VIDEO, the capital of Banda Oriental, and at MALDONADO, a town in
the same province, situated on the northern

shore, near the mouth of the estuary of the Plata. These countries
consist either of an undulating surface, clothed with turf, or of
perfectly level plains with enormous beds of thistles. Except on the
banks of the rivers, trees nowhere grow; there are, however, thickets
in some of the valleys, in the more hilly parts of Banda Oriental.
During the winter and spring of this hemisphere, a considerable
quantity of rain falls, and the plains of turf are then everywhere
verdant; but in summer the country assumes a brown and parched
appearance.

BAHIA BLANCA forms a large bay, in latitude 39° S. on a part of the
coast, which falls within the territory of the province of Buenos
Ayres, but which from its physical conditions would more properly be
classed with Patagonia. The tertiary plains of PATAGONIA, extend from
the Strait of Magellan to the Rio Negro, which is commonly assumed as
their Northern boundary. This space of more than seven hundred miles in
length, and in breadth reaching from the Cordillera to the Atlantic
Ocean, is everywhere characterised by the dreary uniformity of its
landscape. Nearly desert plains, composed of a thick bed of shingle,
and often strewed over with sea-shells, (plainly indicating that the
land has been covered within a recent period by the sea,) are but
rarely interrupted by hills of porphyry, and other crystalline rocks.
The plains support scattered tufts of wiry grass, and stunted bushes;
whilst in the broad flat-bottomed valleys, dwarf thorn-bearing trees,
barely ornamented with the scantiest foliage, sometimes unite into
thickets; and here the few feathered inhabitants of these sterile
regions resort. There is an extreme scarcity of water; and where it is
found, especially if in lakes, it is generally as salt as brine. The
sky in summer is cloudless, and the heat in consequence, considerable;
whereas the frosts of winter are, sometimes, severe. The principal
localities visited by the Beagle, were the RIO NEGRO, in latitude 41°
S., PORT DESIRE, PORT ST. JULIAN, and SANTA CRUZ. At the latter place,
a party, under the command of Captain FitzRoy, followed up the river in
boats, to within a few miles of the Cordillera; and an opportunity was
thus afforded of verifying the nature of the country in its entire
breadth. At the Rio Negro the plains are much more thickly covered with
bushes, (chiefly acacias,) than in any other part of Patagonia.

TIERRA DEL FUEGO may be supposed to include all the broken land
south of a line joining the opposite mouths of the Strait of Magellan.
The land is moun-

tainous, and may be aptly compared to a lofty chain, partly
submerged in the sea; —bays and channels occupying the position of
valleys. The Eastern side almost exclusively consists of clay-slate;
the Western, of primary, and various plutonic formations. The
mountains, from the water's edge, to within a short distance of the
lower limit of perpetual snow, are everywhere (excepting on the exposed
western shores) concealed by an impervious forest, the trees of which
do not periodically shed their leaves. On the East coast, the outline
of the land shows that tertiary formations, like those of Patagonia,
extend south of the Strait of Magellan; but with the exception of this
part, it is rare to find even a small space of level ground; and where
such occurs, a thick bed of peat invariably covers the surface. The
climate is of that kind which has been denominated insular: the winters
are far from being excessively cold, whilst the summers are gloomy,
boisterous, and seldom cheered by the rays of the sun. In all seasons,
a large quantity of rain falls. Hence, from the physical conditions of
Tierra del Fuego, all the land animals must live either on the sea
beach, (and in this class the Aborigines may be included) or within the
humid and entangled forests.

The FALKLAND ISLANDS are situated in the same latitude as the
Eastern entrance of the Strait of Magellan, and about 270 miles East of
it. The climate is nearly the same as in Tierra del Fuego, but the
surface of the land, instead of being as there, concealed by one great
forest, does not support a single tree. We see on every side a withered
and coarse herbage, with a few low bushes, which spring from the peaty
soil of an undulating moorland. Scattered hills, and a central range of
quartz rock, protrude through formations of clay-slate and sand-stone
(belonging to the Silurian epoch,) which compose the lower country.

The structure of the west coast of South America, from the Strait of
Magellan northward to latitude 38°, in its greater part, (as far north
as Chiloe) is very similar to that of Tierra del Fuego. The climate
likewise is similar,—being gloomy, boisterous, and extremely humid;
and, consequently, the land is concealed by an almost impenetrable
forest. In the northern part of this region, the temperature of course
is considerably higher than near the Strait of Magellan; but
nevertheless it is much less so, than might have been anticipated from
so

great a change in latitude. Hence, although the vegetation of this
northern district presents a marked difference when compared with that
of the southern; yet the zoology in many respects has, like the general
aspect of the landscape, a very uniform character. The specimens were
chiefly collected from the PENINSULA OF TRES MONTES, the CHONOS
ARCHIPELAGO (from latitude 46° to 43° 30'), CHILOE with the adjoining
islets, and VALDIVIA. The contrast between the physical conditions and
productions of the East and West coasts of this part of South America
is very remarkable. On one side of the Cordillera, great heavy clouds
are driven along by the western gales in unbroken sheets, and the
indented land is clothed with thick forests; whilst on the other side
of this great range, a bright sky, with a clear and dry atmosphere,
extends over wide and desolate plains.

CHILE in the neighbourhood of CONCEPCION (latitude 36° 42' S.) may
be called a fertile land; for it is diversified with fine woods,
pasturage, and cultivated fields. But towards the more central
districts (near VALPARAISO and SANTIAGO) although by the aid of
irrigation, the soil in the valleys yields a most abundant return, yet
the appearance of the hills, thinly scattered with various kinds of
bushes and cylindrical Opuntias, bespeaks an arid climate. In winter,
rain is copious, but during a long summer of from six to eight months,
a shower never moistens the parched soil. The country has a very alpine
character, and is traversed by several chains of mountains extending
parallel to the Andes. These ranges include between them level basins,
which appear once to have formed the beds of ancient channels and bays,
such as those now intersecting the land further to the south. North of
the neighbourhood of Valparaiso, the climate rapidly becomes more and
more arid, and the land in proportion desert. Beyond the valley of
COQUIMBO (latitude 30°.) it is scarcely habitable, excepting in the
valleys of Guasco, Copiapó, and Paposa, which owe their entire
fertility to the system of irrigation, invented by the aboriginal
Indians and followed by the Spanish colonists. Northward of these
places, the absolute desert of Atacama forms a complete barrier, and
eastward, the snow-clad chain of the Cordillera separates the
Zoological province of Chile, from that of the wide plains which extend
on the other side of the Andes.

The last district which it is at all necessary for me to mention
here, is that

of the GALAPAGOS ARCHIPELAGO, situated under the Equator, and
between five and six hundred miles West of the coast of America. These
islands are entirely volcanic in their composition; and on two of them
the volcanic forces have within late years been seen in activity. There
are five principal islands, and several smaller ones: they cover a
space of 2° 10' in latitude, and 2° 35' in longitude. The climate, for
an equatorial region, is far from being excessively hot: it is
extremely dry; and although the sky is often clouded, rain seldom
falls, excepting during one short season, and then its quantity is
variable. Hence, in the lower part of these islands, even the more
ancient streams of lava (the recent ones still remaining naked and
glossy) are clothed only with thin and nearly leafless bushes. At an
elevation of 1200 feet, and upwards, the land receives the moisture
condensed from the clouds, which are drifted by the trade wind over
this part of the ocean at an inconsiderable height. In consequence of
this, the upper and central part of each island supports a green and
thriving vegetation; but from some cause, not very easily explained, it
is much less frequented, than the lower and rocky districts are, by the
feathered inhabitants of this archipelago.

By a reference to the localities here described, it is hoped that
the reader will obtain some general idea of the nature of the different
countries inhabited by the several animals, which will be described in
the following sheets.

The vertebrate animals in my collection have been presented to the
following museums: — the Mammalia and Birds to the Zoological Society;
the Fishes to the Cambridge Philosophical Society; and the Reptiles,
when described, will be deposited in the British Museum. For the care
and preservation of all these and other specimens, during the long
interval of time between their arrival in this country and my return, I
am deeply indebted to the kindness of the Rev. Professor Henslow of
Cambridge. With respect to the gentlemen, who have undertaken the
several departments of this publication, I hope they will permit me
here to express the great personal obligation which I feel towards
them, and likewise my admiration at the disinterested zeal which has
induced them thus to bestow their time and talents for the good of
Science.

DESCRIPTION.—The fur of this Bat is glossy and has a silk-like
appearance; that on the top of the head, sides of the face, and the
whole of the upper parts of the body, is of a deep brown colour; all
the hairs on these parts, however, are white at the base. The flanks,
interfemoral membrane, and the arms, are also covered on their upper
side with brown hairs. On the lower part of the sides of the face, and
the whole of the under parts of the body, the hairs are of an
ashy-white colour. The membrane of the wing is brownish. The ears are
of moderate size, and somewhat pointed; externally they are covered
with minute brown hairs, and internally with white. The tragus is also
covered with white hairs; it is of a narrow form, pointed at the tip,
and has a small acute process in the middle of the outer margin. The
nose-leaf is pierced by the nostrils, which diverge posteriorly, and is
so deeply cleft on its hinder margin, that it may be compared to two
small leaflets joined side by side near their bases. These leaflets,
unlike the nose-leaf of the Phyllostomina, lie horizontally on the nose
to which they are attached throughout, a slight ridge only indicating
their margin. Around the posterior part of the nose-leaf there is a
considerable naked space, in which two small hollows are observable,
situated one on each side, and close to the

nose-leaf; and, at a short distance behind the nose-leaf, this naked
membrane is slightly elevated, and forms a transverse fleshy tubercle.

In.

Lines.

In.

Lines.

Length of

head and body . . .

3

3

Length of

tarsus (claw included) . .

0

81/3

interfemoral membrane . .

0

3½

ear . . . . .

0

4

the antibrachium . . .

2

2

tragus . . . . .

0

3

thumb (claw included) . .

0

8

nose-leaf . . . .

0

2¼

tibia . . . . .

0

10

Expanse of

the wings . . . .

12

8

Habitat, Coquimbo, Chile. (May.)

"The Vampire Bat," says Mr. Darwin in his MS. notes upon the present
species, "is often the cause of much trouble, by biting the horses on
their withers. The injury is generally not so much owing to the loss of
blood, as to the inflammation which the pressure of the saddle
afterwards produces. The whole circumstance has lately been doubted in
England; I was therefore fortunate in being present when one was
actually caught on a horse's back. We were bivouacking late one evening
near Coquimbo, in Chile, when my servant, noticing that one of the
horses was very restive, went to see what was the matter, and fancying
he could distinguish something, suddenly put his hand on the beast's
withers, and secured the Vampire. In the morning, the spot where the
bite had been inflicted was easily distinguished from being slightly
swollen and bloody. The third day afterwards we rode the horse, without
any ill effects.

Before the introduction of the domesticated quadrupeds, this Vampire
Bat probably preyed on the guanaco, or vicugna, for these, together
with the puma, and man, were the only terrestrial mammalia of large
size, which formerly inhabited the northern part of Chile. This species
must be unknown, or very uncommon in Central Chile, since Molina, who
lived in that part, says (Compendio de la Historia del Reyno de Chile,
vol. i. p. 301,) "that no blood-sucking species is found in this
province."

It is interesting to find that the structure of this animal is in
perfect accordance with the habits as above detailed by Mr. Darwin.
Among other points, the total absence of true molars, and consequent
want of the power of masticating food, is the most remarkable. On the
other hand we find the canines and incisors perfectly fitted for
inflicting a wound such as described, while the small size of the
interfemoral membrane (giving freedom to the motions of the legs,)
together with the unusually large size of the thumb and claw, would
enable this Bat, as I should imagine, to fix itself with great security
to the body of the horse.

I have named this species after M. d'Orbigny, who has added so much
to

our information on the zoological productions of South America. The Edostoma
cinerea* of that author has evidently a close affinity to the
animal here described, and differs chiefly (judging from the drawing
published in his work) in the larger size of the ears, in having the
nose-leaf free, and the surrounding membrane free and elevated.

As M. d'Orbigny has not yet published the character of his genus Edostoma,
his figure is my only guide, and in this figure I find the dentition
agreeing both with that of the present species, and that of the genus Desmodus
of Prince Maximilian,—as would appear from the published
descriptions, and figure given by M. de Blainville†.—The points of
distinction between M. d'Orbigny's animal and the species here
described, are not, in my opinion, of sufficient importance to
constitute generic characters, I have, therefore, retained the name of
Desmodus.

It is desireable perhaps to separate the Blood-sucking Bats from the
Insectivorous species, and place them between the latter group and the Pteropina,
(with which they agree in the large size of the thumb and the
rudimentary interfemoral membrane,) under a sectional name, which I
propose to call Hæmatophilini.

DESCRIPTION.—This Phyllostoma agrees with the species described by
Mr. J. Gray‡ under the name of Childreni, in having on the lower lip
"an half ovate group of crowded warts," but is of a much smaller size,
and differs also in colour.

The number of teeth are as follows: —incisors 4/4; canines 2/2;
molars 5-5/5-5 = 32. The intermediate pair of incisors of the upper jaw
are large, compressed, and have their apices rounded; the lateral pair
are so minute, that they are scarcely visible without the assistance of
a lens: the four incisors of the

lower jaw, are somewhat crowded, the intermediate pair are slightly
larger than the lateral; they are all deeply notched, and broad at the
apex. The cerebral portion of the skull is much arched and the anterior
portion is depressed. The zygomatic arch is imperfect; see Pl. 35.
figs. 2. The nose-leaf is lanceolate, and of moderate size: the ears
are also of moderate size; they are rounded at the tip and emarginated
on their exterior edge: the tragus is elongated, and suddenly
attenuated towards the apex; the outer margin is deeply notched towards
the base, and very obscurely crenulated above this notch. The
interfemoral membrane is of moderate extent, and emarginated
posteriorly. The tail, which is very slender, is entirely enclosed by
the interfemoral membrane, and the visible portion appears to consist
of but two joints, which together, measure about two and a half lines
in length. The basal half of the thumb is enclosed in membrane. The fur
is soft and rather long. The general tint of the upper and under parts
of the body is brownish-ash; the hairs on the neck and on the whole of
the back are grey at the base, then white, or nearly so, brownish-ash
near the tip, and whitish at the tip. On the belly the hairs are nearly
of an uniform brown-ash colour, their apices only being whitish. The
ears, nose-leaf, and membrane of the wings, are of a sooty-black hue.

In.

Lines.

In.

Lines.

Length of

head and body . . .

2

0

Length of

ear . .

0

7

antibrachium . . .

1

41/3

nose-leaf . . . .

0

3½

thumb (claw included) . .

0

5½

Expanse of

the wings . . . .

10

0

tibia . . . . .

0

7

Habitat, Pernambuco, Brazil. (August.)

"This species appeared to be common at Pernambuco (five degrees
north of Bahia). Upon entering an old lime-kiln in the middle of the
day, I disturbed a considerable number of them: they did not seem to be
much incommoded by the light, and their habitation was much less dark
than that usually frequented as a sleeping place by these animals." D.

I have named this species after Mr. John Gray, the author of several
extensive memoirs on the order to which it belongs, and to whom I am
indebted for valuable assistance whilst comparing this and other
species with those contained in the collection of the British Museum.

2. PHYLLOSTOMA PERSPICILLATUM.

I find in Mr. Darwin's collection, a bat agreeing with the
description of M.

Geoffroy Saint Hilaire,* under the above name, with the exception of
a slight difference in the dimensions; I will, therefore, add those of
the present specimen, which is a female. It may be observed, that in
the animal before me, the tragus of the ear is pointed, and not bifid
at the apex, as represented in plate xi of the work quoted.

In.

Lines.

In.

Lines.

Length of

head and body . . .

4

0

Length of

tragus . .

0

3

antibrachium . . .

2

7

tibia . . . .

1

0

nose-leaf . . . .

0

5

Expansion of

the wings . . . .

16

8

ear . . . . .

0

8½

"This bat was caught at Bahia, (latitude 13° S.) on the coast of
Brazil, in consequence of its having flown into a room where there was
a light. I scarcely ever saw an animal so tenacious of life." D.

DESCRIPTION.—In size and colouring, this Bat very closely resembles
the Vespertilio Pipistrellus of Europe; the wings, however,
are considerably broader in proportion; the antibrachium, tibia, and
tail, are each of them longer; the tragus of the ear is also longer,
and narrower.

The muzzle is short and obtuse, and furnished on each side with
numerous hairs, which, when compared with those of other parts, are of
a more harsh nature. The nose is naked at the apex. The forehead is
concave. The ears are narrow, and somewhat pointed, emarginated
externally, and have about four transverse rugæ: the tragus is
elongated, narrow, and pointed, and has the outer margin very obscurely
crenulated. On the chin there is a small wart, from which spring
several stiffish hairs. The tail is about equal to the body in length,
and has the extreme tip free. The fur is moderately

long, and of an uniform rich brown colour, and extends on to the
base of the interfemoral membrane above and below; the remainder of
this membrane is bare, and, together with that of the wings, of a black
colour.

In.

Lines.

In.

Lines.

Length of

the head and body . . .

1

8

Length of

the tragus . .

0

31/3

the tail . . . .

1

3½

the antibrachium . . .

1

5½

Expanse of

the wings . . . .

8

3

the thumb (claw included) .

0

2½

Length of

the ear . . . . .

0

5½

the tibia . . . .

0

6¾

Habitat, Chiloe. (January.)

"This specimen was given me by Lieut. Sulivan, who obtained it
amongst the islets on the Eastern side of Chiloe. It is not, I believe,
common, nor do the humid and impervious forests of that island appear a
congenial habitation for members of this family. It must, however, be
observed, that even in Tierra del Fuego, where the climate is still
less hospitable, and where the number of insects is surprisingly small,
I saw one of these animals on the wing." D.

OF this species I find three specimens in Mr. Darwin's collection —
"It is remarkable," says Mr. Darwin, "for its wide geographical range.
I obtained specimens at Maldonado, on the northern bank of the Plata,
where it was exceedingly numerous in the attics of old houses, and
likewise at Valparaiso in Chile. Molina (vol. i. p. 301.) says another
species is found in Chile, of the same size and figure, but of a more
orange (naranjado) colour."

Upon comparing the dimensions of several specimens of this species
with those given by Temminck in his "Monographie sur le Genre Molosse,"
I find that they vary very considerably; I shall therefore be adding
some little to the history of the species, by giving the dimensions of
those now before me, together with the sexes of the specimens measured,
and their localities. In all these specimens there is a series of
pointed tubercles along the upper margin of the ears, a character which
M. Temminck has omitted to notice. They vary slightly

in the intensity of their colouring, but among those brought from
Chile I do not perceive any agreeing with that species, or variety,
mentioned by Molina as approaching to an orange colour. All the
specimens whose dimensions are here given, are preserved in spirit. Two
of them are from Maldonado brought by Mr. Darwin; three were collected
in Hayti by Mr. J. Hearne, and one is from Chile, whence it was brought
by Mr. H. Cuming.

From Chile.

Hayti.

Hayti.

Hayti.

Maldonado.

Maldonado.

♀

♀

♂

♂

♀

♀

In.

Lines.

In.

Lines.

In.

Lines.

In.

Lines.

In.

Lines.

In.

Lines.

Length

of head and body . .

2

3

1

11

2

0

2

0½

2

6

2

6

of tail . . . .

1

1½

1

2

1

2

1

1½

1

1

1

2

of free portion of ditto .

0

6½

0

5

0

6½

0

51/3

0

8¾

0

8½

Expanse
of wings . .

10

3

9

3

9

8

9

0

10

6

10

2

Length

of antibrachium . .

1

7

1

6

1

6½

1

6

1

8

1

9

of
ears . . .

0

5

0

4½

0

4¾

0

4½

0

51/3

0

5½

Width of
ditto . . .

0

7

0

6

0

6

0

6

0

7

0

7

Length
from nose to eye . .

0

3½

0

3

0

3¾

0

3

0

3½

0

3½

In all the specimens examined by me, there are two incisors in the
upper jaw, and four in the lower, they would therefore, according to M.
Temminck, be adult.

DESCRIPTION.—This animal is considerably larger than the common fox,
(Canis Vulpes, Auct.) and stouter in its proportions, and, in
fact, appears to be intermediate between the ordinary foxes and the
wolves. The tail is much

smaller and less bushy than in the former animals. The contour of
the head is wolf-like; the legs, however, are shorter than in the true
wolves; and the tail is white at the apex, a character common in the
foxes.

The fur of the Antarctic Fox is moderately long, and the under fur
is not very abundant, especially as compared with that of the C. magellanicus.
This under fur is of a pale brown colour; the apical portion of
each hair is yellowish; the longer hairs are black at the apex, brown
at the base, and annulated with white towards the apex. In many of
these hairs the subapical pale ring is wanting. On the chest and belly
the hairs are of a pale dirty yellow colour, gray-white at the base,
and black at the apex. On the hinder part of the belly the hairs are
almost of an uniform dirty white. The space around the angle of the
mouth, the upper lip, and the whole of the throat, are white. The chin
is brown-white, or brownish. The basal half of the tail is of the same
colour as the body, and the hairs are of the same texture; on the
apical half of the tail they are of a harsher or less woolly nature, of
a black colour at the apex, and brownish at the base; those at the
extreme point are totally white. The legs are almost of an uniform
fulvous colour; the feet are of a somewhat paler hue; the hairs on the
under side of the hinder feet are brownish, and the external and
posterior parts of the tibiæ are suffused with the same tint. The hairs
on the head are grizzled with black and fulvous; the former of these
colours is somewhat conspicuous, excepting in the region of the eyes,
where the fulvous or yellowish tint prevails. The muzzle is scarcely of
so dark a hue as the crown of the head. The ears are furnished
internally with long white hairs, externally the hairs are yellowish,
with their apices black; the latter colour is more conspicuous towards
the tip of the ear. The sides of the neck near the ear are of a rich
fulvous hue.

In.

Lines.

In.

Lines.

Length

from nose to root of tail . .

36

0

Length of

ear . .

2

9

from tip of nose to ear . .

7

3

Height of

body at shoulders . .

15

0

of tail (hair included) . .

13

0

Habitat, Falkland Islands.

"Three specimens of this animal were brought to England by Capt.
FitzRoy; from one of which, the above drawing and description has been
made. The earliest notice I can find of this animal is by Pernety,*
during Bougainville's voyage, which was undertaken in 1764, for the
purpose of colonizing these islands. The strange familiarity of its
manner seems to have excited the fears of some of

the seamen in Commodore Byron's voyage (in 1765) in rather a
ludicrous manner. Byron says that seals were not the only dangerous
animals that they found, "for the master having been sent out one day
to sound the coast upon the south shore, reported at his return that
four creatures of great fierceness, resembling wolves, ran up to their
bellies in the water to attack the people in his boat, and that as they
happened to have no fire-arms with them, they had immediately put the
boat off in deep water." Byron adds that, "When any of these creatures
got sight of our people, though at ever so great a distance, they ran
directly at them; and no less than five of them were killed this day.
They were always called wolves by the ship's company, but, except in
their size, and the shape of the tail, I think they bore a greater
resemblance to a fox. They are as big as a middle-sized mastiff, and
their fangs are remarkably long and sharp. There are great numbers of
them upon this coast, though it is not perhaps easy to guess how they
first came hither; for these islands are at least one hundred leagues
distant from the main. They burrow in the ground like a fox, and we
have frequently seen pieces of seals which they have mangled, and the
skins of penguins lie scattered about the mouths of their holes. To get
rid of these creatures, our people set fire to the grass, so that the
country was in a blaze as far as the eye could reach, for several days,
and we could see them running in great numbers to seek other quarters."

The habits of these animals remain nearly the same to the present
day, although their numbers have been greatly decreased by the singular
facility with which they are destroyed. I was assured by several of the
Spanish countrymen, who are employed in hunting the cattle which have
run wild on these islands, that they have repeatedly killed them by
means of a knife held in one hand, and a piece of meat to tempt them to
approach, in the other. They range over the whole island, but perhaps
are most numerous near the coast; in the inland parts they must subsist
almost exclusively on the upland geese, (Anser leucopterus,)
which, from fear of them, like the eider-ducks of Iceland, build only
on the small outlying islets. These wolves do not go in packs; they
wander about by day, but more commonly in the evening; they burrow
holes; are generally very silent, excepting during the breeding season,
when they utter cries, which were described to me as resembling those
of the Canis Azaræ. Spaniards and half-cast Indians, from
several districts of the southern portions of South America, have
visited these islands, and they all declare that the wolf is not found
on the mainland; the sealers likewise say it does not occur on Georgia,
Sandwich Land, or the other islands in the Antarctic ocean. I
entertain, therefore, no doubt, that the Canis antarcticus is
peculiar to this archipelago. It is found both on East and West
Falkland, as might have been inferred from the accounts given by
Bougainville and Byron, who visited different islands; —I state this
particularly, because the contrary has been asserted. I was

assured by Mr. Low, an intelligent sealer, who has long frequented
these islands, that the wolves of West Falkland are invariably smaller
and of a redder colour than those from the Eastern island; and this
account was corroborated by the officers of the Adventure, employed in
surveying the archipelago. Mr. Gray, of the British Museum, had the
kindness to compare in my presence the specimens deposited there by
Captain Fitzroy, but he could not detect any essential difference
between them. The number of these animals during the last fifty years
must have been greatly reduced; already they are entirely banished from
that half of East Falkland which lies East of the head of St. Salvador
Bay and Berkeley Sound; and it cannot, I think, be doubted, that as
these islands are now becoming colonized, before the paper is decayed
on which this animal has been figured, it will be ranked amongst those
species which have perished from the face of the earth."—D.

DESCRIPTION.—This species is considerably larger than the European
fox; its form is more bulky, the limbs are shorter and stouter in
proportion, the ears are smaller and the tail is more bushy. The fur is
long, thick, and loose. The under fur is very long, abundant, and of a
woolly texture. The back is mottled with black and white, the former of
these colours being predominant; the hairs on this part are gray at the
base, there is then a considerable space of a pale, or whitish brown
colour; next follows a broad white ring, beyond which the hairs are
black. On the sides of the body the hairs are coloured in the same way,
excepting that the white portion is more extended, and is followed by a
rich yellow-brown, shaded into black as it approaches the apex of each
hair. Hence the general hue of the sides of the body is paler than that
of the back, the brown and white tints being the more conspicuous.

The hairs of the head are annulated with white, and fulvous, and are
black at the tip; the two former colours are most conspicuous. The chin
is brownish. The lower part of the cheeks, the throat, and the under
parts of the body, are of a dirty yellowish white colour, inclining to
buff in certain parts, especially on the lower part of the neck and
chest. The limbs are of a rich deep fulvous, or yellowish rust colour
externally; the feet and inner sides of the legs are of a paler hue. On
the hinder legs externally, above the heel, is a patch of bright rust
colour; such is also the colour of the ears externally, and likewise of
that portion of the neck behind the ears. Internally the ears are
furnished with long yellowish white hairs. The tail is long and very
bushy; at its base the hairs are rusty white, towards the middle they
are of a paleish rust colour, and at the apex they are black; there is
also a black patch on the upper part towards the base. The hairs of the
tail beneath are almost entirely of an uniform rusty white colour,
those on the upper side are all tipped with black.

In.

Lines.

In.

Lines.

Length

from nose to root of tail . .

31

0

Length of ear . . . . .

2

0

to base of ear . .

6

9

Height of body at the
shoulders . .

14

6

of tail (hair included) . .

17

0

Habitat, Chile. (June.)

"This animal was first brought to Europe by Captain Philip P. King,
who obtained it at Port Famine in Tierra del Fuego, where it is common.
My specimen was obtained in the valley of Copiapó in the northern part
of Chile. The Magellanic fox, therefore, has a range on the western
coast of at least 1600 miles, from the humid and entangled forests of
Tierra del Fuego, to the almost absolutely desert country of northern
Chile. In La Plata, on the Atlantic side of the continent, I believe it
is not found.* It is mentioned by Molina in his account of the animals
of Chile,† under the name of Culpeu, which he supposes to be derived
from the Indian word "culpem," signifying madness; for this animal,
when it sees a man, runs towards him, and standing at the distance of a
few yards, looks at him attentively. He adds, although great numbers
are killed, they do not leave off this habit. Molina states that he has
repeatedly been a witness of this, and I received nearly similar
accounts from several of the inhabitants of Chile: yet I must observe,
that the people of the farm-house, where my specimen was killed

* Azara has not described this animal, which
circumstance alone would render it probable that it is not an
inhabitant of Paraguay or La Plata. The two Foxes mentioned by him are
the Aguará-guaza, (Canis jubatus, Auct.) a very large kind of
fox (a strangely exaggerated description of this animal is given by
Falkner) of which I could not obtain a specimen; and the Aguará-chay,
or Canis Azaræ.

(after it, together with its female, had destroyed nearly two
hundred fowls) bitterly complained of its craftiness. From this bold
curiosity in the disposition of the Culpeu, Molina thought that it was
the same animal as that described by Byron at the Falkland Islands, but
we now know that they are different. The Culpeu burrows holes under
ground, often wanders about by day, is very strong and fleet. When
riding one day in the valley of Copiapó, accompanied by a half-bred
greyhound, I happened to come across one of these foxes; and although
the ground was, in the first part of the chase, level, it soon entirely
distanced its pursuer. Whilst running, it barked so like a dog, that
until it had run some way a-head of the greyhound, I could not tell
from which animal the noise proceeded. After the Culpeu had reached the
mountains, it made a sudden bend from its course, and returned in a
nearly parallel line, but at the base of a steep cliff of rock; it then
quietly seated itself on its haunches, and seemed to listen with much
satisfaction to the dog, which was running the scent on the mountain
side, above its head."—D.

DESCRIPTION.—This species is considerably less than the common
European fox, (Canis Vulpes, Auct.) its weight probably would
scarcely exceed half that of the latter animal. The form of the body is
stout, the limbs are short and rather slender; the head is also short,
and the muzzle is pointed; the ears are of moderate size. The tail is
about equal to half the whole length of the body, head included; and
compared with that of ordinary foxes, is much less bushy, especially at
the base. The general hue of this animal is very dark; the fur is
rather short, and harsh to the touch; the under fur is abundant, and of
a woolly texture. On the back, all the hairs are of a deep brown
colour, annulated with white near the apex, and black at the apex. When
the fur is

in its ordinary position, the brown colour is not seen, and the
black and white produce a grizzled appearance; the black colour,
however, predominates. On the sides of the body each hair is grayish at
the base, then pale brown, near the apex annulated with white, and at
the apex black: the three last mentioned colours are exhibited in about
equal proportions (the fur being in its natural position) over the
haunches and shoulders, but between these two parts, the brown and
white colours are the more conspicuous. The hairs of the head are
coloured in the same way as those of the sides of the body, excepting
that the brown portion of each hair, is replaced by rusty brown, which
gives a rufous hue to this part. The muzzle and chin are of a sooty
brown colour. A dirty white patch is observable on each side of the
muzzle at the apex, and this colour is extended along the margin of the
upper lip on to the lower part of the cheeks, and over the whole of the
throat; all the hairs in these parts (with the exception of those on
the lips) being of a deep brownish gray colour, with their apical
portions only, white. The ears are covered internally with long
yellowish white hairs; towards, and on the margin of the ears
externally, the hairs are of a buff colour, on the remaining portion of
the ears, and on the sides of the neck, they are of a reddish chestnut
hue. The hairs of the under parts of the body are brown, those near the
hinder legs, and between them, are of a dirty white colour at the apex;
towards the rump they are of a yellowish brown colour. The hairs of the
tail are brown, black at the apex, and annulated with white near the
apex; on the apical portion the hairs are black, and brown at the base.
The fore legs are of a brown colour externally, internally they are of
a brownish fulvous hue; such is also the colour of the feet. The fore
part of the posterior legs is whitish, and there is a large blackish
patch on the outer side, and extending around the posterior part, above
the heel.

In.

Lines.

In.

Lines.

Length

from nose to root of tail . .

24

0

Length of ear . . . . .

2

3½

to base of ear . .

0

4¾

Height of body at shoulders .
.

10

6

of tail (hair included) . .

10

0

Habitat, Chiloe. (December.)

"I killed this animal on the sea-beach, at the southern point of the
island; it is considered extremely rare in the northern and inhabited
districts. Molina mentions this fox, which he falsely considered as the
C. lagopus, under the name of the Payne Gurú, and
he adds, that in the Archipelago of Chiloe, it is found of a black
colour. From this circumstance I am induced to believe that the species
is confined to these islands."—D.

DESCRIPTION.—Compared with the common fox (Canis Vulpes,
Auct.), the present animal is rather smaller, and of a more slender
form. Its limbs are a little longer in proportion; the ears are not so
broad. The tail is not quite so bushy, neither is it so long; the fur
is much longer, and of a harsher nature.

The predominant colours of the body are black and white; the limbs
are of a fulvous hue externally. The hairs on the under part of the
feet are dirty brown; the fore part of the anterior legs, and the feet,
are of a buff colour; on the former, the hairs are more or less
distinctly tipped with black, which produces a grizzled appearance. The
inner side of the fore legs is of an uniform pale buff colour; the
hinder part of these legs, the fore part of the posterior legs, and the
inner side of the thighs, are white. On the outer side of the hinder
legs, at some little distance above the heel, is a large blackish
patch. The under parts of the body are of a dirty white hue, arising
from the hairs being dusky or brownish at the base, and tipped with
white, as on the fore part of the belly, or of a pale buff colour at
the base, as towards the rump. The edge of the upper lip, the throat,
neck, and chest, are white; a broad grayish band extends across the
latter, and another of a paler hue crosses the lower part of the neck.
The chin is black, and this colour is extended backwards around the
angle of the mouth. The upper part of the head is of a pale
yellow-brown colour, each hair being annulated with white near the
apex. The ears are furnished with white hairs internally, and
externally they are of a yellowish brown colour, tipped with black; at
the base of the ears, and the portion of the neck on each side nearest
to them, the

hairs are of an uniform buff colour. The hairs of the moustaches are
long and stiff, and of a black colour. The hairs of the back, which are
very long, are brown at the base, very pale towards the skin, and of a
deep brown in the opposite direction; each hair is then white, and at
the apex black. The tail is whitish, mottled with black; the apical
portion is black, and there is a patch of the same colour towards the
base on the upper side.

In.

Lines.

In.

Lines.

Length

from nose to root of tail . .

27

6

Length of ear . . . . .

3

2

to base of ear . .

5

9

Height of body at shoulders .
.

14

0

of tail (hair included) . .

14

6

Habitat, La Plata, Patagonia, and Chile.

The black and white portions of the hairs on the back produce in
that part a mottled appearance, and in the specimen from which the
above description is taken, these two colours are about equal in
proportion. In another specimen now before me, the black colour
predominates on the back. The fur in the younger animals of this
species is not so long nor so harsh, and the upper parts are grizzled
with black and white; that is to say, these two colours do not form
patches of considerable extent as in the adults; the general colouring
is also somewhat paler. The chin is brown-black or brown, instead of
black, and the upper band, or that, which in the adult extends across
the upper part of the neck, is interrupted in the middle; in fact, is
only traceable on the sides of the neck.

Azara, in his description of the Agouarachay, says, the muzzle, as
far back as the eyes, is blackish; whereas, in all the specimens
examined by me, the muzzle is of the same colour as the other parts of
the head, or very nearly so. In other respects his
description agrees with the animal described by me, and not with
the Canis cinereo-argentatus, which Desmarest and Lesson
suppose to be the Agouarachay of Azara. In Fischer's "Synopsis
Mammalium" the Canis Azaræ is described as having the
tip of the tail white; whereas it is black, not only in the five
specimens which have come under my notice, but also in those in the
collection of Prince Maximilian* (who was the original describer) and
in the Paris Museum.

"This animal has a wide range; Prince Maximilian brought specimens
from Brazil; and it is common in La Plata, Chile, the whole of
Patagonia, even to the shores of the Strait of Magellan; and a fox,
which lives on the small islands not far from Cape Horn, probably
belongs to this species. This animal generally frequents desert places;
I saw many in the valley of the Despoblado, a branch of

* I am indebted to Mr. Ogilby, who visited the
Prince's collection, for a description from the specimens of C.
Azaræ therein preserved. In this description the tip of the tail
is said to be black.

that of Copiapó, where there is no fresh water, and where, with the
exception of some small rodents, (the constant inhabitants of sterile
regions) scarcely any other animal could exist. I saw also very many of
these foxes wandering about by day (although Azara says they are
nocturnal in Paraguay) on the plains of Santa Cruz, where various kinds
of mice are abundant, and likewise around the Sierra Ventana. In the
course of one day's ride in this latter neighbourhood, (not far from
Bahia Blanca, lat. 39° S.) I should think I saw between thirty and
forty. They generally were wandering at no great distance from their
burrows; but, as they are not very swift animals, our dogs caught two.
Azara states that in Paraguay this fox, which he calls the Agourá-chay,
inhabits thick woods, and that it makes a great nest or pile of straw,
to lie on; but that near Buenos Ayres it uses the holes of the
Bizcacha. Further southward, where the Bizcacha is not found, it
certainly excavates its own burrow.* In Chile these foxes are very
destructive to the vineyards, from the quantity of grapes they consume;
so that boys are generally kept in the vintage season with bells and
other means to frighten them away. Azara states, that in Paraguay they
likewise eat fruit and sugar-cane. By the same authority it is said,
that the Agourá-chay, when taken young, is easily domesticated."—D.

DESCRIPTION.—The fur is rather harsh, short, and somewhat adpressed:
the under fur is of a pale grayish brown colour; the hairs which
constitute the chief clothing of the animal, are black, annulated with
brownish yellow, or in some parts, yellow-white, each hair having about
three or four rings. The black and pale colours are about equal in
proportion, and their mixture pro-

* Considering the great difference of climate and
other conditions between the hot and wooded country of Paraguay, and
the desolate plains of Patagonia, one is led to suspect that the Canis
Azaræof La Plata and Patagonia, which wanders
about by day, and inhabits burrows instead of heaps of straw, may turn
out to be a different species from the Agouará-chay of Azara, which is
nocturnal in its habits, and lives in thick coverts.

duces a deep brown tint, which is almost uniform throughout the body
and limbs. On the head the yellowish colour predominates over the
black, excepting on the tip of the muzzle, and thence back to the eye,
where the hairs are of a brownish black colour. On the throat the hairs
are brown. The underside of the tarsus is black, and on the outer side
of the fore-foot there is a black mark which extends upwards on to the
wrist. The tail is long and bushy; towards and on the base, the hairs
are annulated with black and yellow, like those of the body; but beyond
this they are of a more uniform colour, each hair being brown at the
base, and gradually shaded into black towards the tip. The ears are
small and rounded, and covered with hairs of the same colour as those
on the head. The claws are of a large size, and white colour; the toes
are united for a considerable portion of their length by the
interdigital membrane.

In.

Lines.

In.

Lines.

Length

from nose to root of tail . .

25

0

Length of ear . . . . .

1

0

to base of ear . .

3

6

Height of body at shoulders .
.

12

0

of tail (hairs included) . .

19

0

Habitat, Rio de Janeiro, Brazil. (May.)

"This cat was given me by an old Portuguese priest, who had hunted
it down in a thick forest with a small pack of dogs, after a severe
chase. It was killed near the Gavia mountain, at the distance of a few
miles only from Rio de Janeiro, where it was considered uncommon." D.
Although small, compared with the Puma, (Felis concolor,
Auct.), this cat, in its slender lengthened body, small head, long
tail, and stout limbs, decidedly evinces an affinity to that species.
According to the dimensions of the Yagouaroundi given by Azara,
Desmarest, and Temminck, it appears that the tail is considerably
shorter in proportion in the specimens examined by those naturalists,
than in the present individual, and the difference was such, as to
induce Mr. Martin to believe that the latter was a distinct species; he
accordingly proposed for it the specific name of Darwinii. At
the time that Mr. Martin described the specimen alluded to, I was also
inclined to believe it was a distinct species. I mention this because I
am afraid my opinion had a slight share in influencing Mr. Martin's
determination. I have since seen many specimens, and upon comparing
their dimensions, I find that the proportionate length of the tail
varies more than is usual in other species of cats, and that the
difference in the length in this member is not combined with any other
distinguishing character. In colouring there is also a considerable
variation, some specimens being almost black, and having the hairs but
obscurely annulated with white; in others, the hairs are more
distinctly annulated, and the head assumes a grayish hue. Others again,
are brown, or black brown,

DESCRIPTION.—The Pampas cat is about equal in size to the common
wild cat of Europe (Felis Catus, Linn.). It is however of a
stouter form than that animal, the head is smaller, and the tail is
shorter.

The most remarkable character in this species consists in the great
length of the fur, — the longer hairs on the back measuring upwards of
three inches, and those on the hinder part of the back, are from four
and a half, to four and three quarter inches in length. The general
colour of the fur is pale yellow-gray. Numerous irregular yellow, or
sometimes brown stripes run in an oblique manner from the back along
the sides of the body. On each side of the face there are two stripes
of a yellowish or cinnamon colour: these stripes commence near the eye,
extend backwards and downwards over the cheeks, on the hinder part of
which they join and form a single line, which encircles the lower part
of the throat. The tip of the muzzle and the chin are white, and there
is a spot in front of the eye, and a line beneath the eye, of the same
colour: the belly and the inner side and hinder part of

* In measuring the species of Mammalia, I almost
invariably, when wishing to give the length, measure from the tip of
the nose along the curve of the back to the root of the
tail. In the Ruminantia of course this plan is not desirable, but in
other Mammals I have found it most convenient. If we take a Cat, for
instance, and curve the body in whatever way we please, we find the
length (taken in the way just mentioned) always the same. Whereas, if
we take a straight line (as many naturalists do) the length will vary
according to the position of the animal.

the fore-legs are also white. An irregular black line runs across
the lower part of the chest and extends over the base of the fore-legs
externally, and above this line there are two other transverse dark
markings on the chest, which are more or less defined. On the fore-legs
there are three broad black bands, two of which encircle the leg, and
on the posterior legs there are about five black bands externally, and
some irregular dark spots internally. The feet are yellowish, and the
underside of the tarsus is of a slightly deeper hue. On the belly there
are numerous large irregular black spots. The ears are of moderate
size, furnished internally with long white hairs; externally, the ears
are of the same colour as the head, excepting at the apex where the
hairs are black and form a slight tuft. The tail is short, somewhat
bushy, and devoid of dark rings or spots — the hairs are in fact
coloured as those of the back of the animal. On the upper part of the
body each hair is brown at the base, then yellow, and at the apex,
black. On the hinder part of the back the hairs are almost black at the
base, and on the sides of the body each hair is gray at the base; there
is then a considerable space of yellowish-white colour; towards the
apex they are white, and at the apex black. The greater number of the
hairs of the moustaches are white.

In.

Lines.

In.

Lines.

Length

from nose to root of tail . .

26

0

Length of ear . . . . .

1

11

to base of ear . .

3

6

Height of body at shoulders .
.

13

0

of tail (fur included) . .

11

0

Habitat, Santa Cruz, Patagonia, (April,) and Bahia Blanca, (August.)

The markings in this animal vary slightly in intensity; those on the
body are generally indistinct, but the black rings on the legs are
always very conspicuous.

"This animal takes its name from ‘paja,’ the Spanish word for straw,
from its habit of frequenting reeds. It is common over the whole of the
great plains, which compose the eastern side of the southern part of
America. According to Azara, it extends northward as far as latitude
30°, and to the south, I have reason to believe, from the accounts I
have received, that it is found near the Strait of Magellan, which
would give it a range of nearly 1400 miles, in a north and south line.
One of my specimens was obtained, in 50° south, at Santa Cruz: it was
met with in a valley, where a few thickets were growing. When
disturbed, it did not run away, but drew itself up, and hissed. My
other specimen was half-grown, and was killed in the end of August, at
Bahia Blanca."—D.

I find in Mr. Darwin's collection a cat, the colouring and
proportions of which, convince me that its origin is from the domestic
cat, as however it was shot in a wild state far from any house, a
description may, perhaps, prove useful. Its general colour is deep
gray, and the body is adorned with numerous irregular narrow black
bands; there is a broad black mark, formed of confluent spots, along
the middle of the back, which commences a little behind the shoulders;
a considerable space around the angles of the mouth, the chin, throat,
central portion of the chest, fore-feet, toes of the hinder feet, and
the posterior portion of the belly, are white; a black line extends
backwards from the posterior angle of the eye, on to the cheeks;
thence, across the throat, there are two lines: the space between the
eye is chiefly occupied with white hairs: the tail is slender, and
tapers towards the apex; the basal half is gray with black rings, and
the apical half is black, excepting the extreme point, which is white:
the tarsus is black beneath: the legs are of a deep gray colour, banded
with black externally.

To the dimensions I will add those of a domestic cat which in colour
and markings very closely resembles the animal above described. I may
add that I have chosen a cat rather above the ordinary size for my
comparison, yet it will be seen that the wild cat has the advantage in
bulk.

Wild Cat.

Domestic Cat.

In.

Lines.

In.

Lines.

Length

from nose to root of tail . .
.

22

0

19

0

of tail . . . . .

12

3

11

6

of tarsus . . . . .

5

1

4

7

of ear . . . . . .

1

11

Height

at shoulders . . . . .

11

3

Habitat, Maldonado, La Plata, (May.)

"This animal was killed amongst some thickets on a rocky hill a few
miles from Maldonado. It appeared, when dead, much larger and stronger
than any domestic cat I ever saw, and it was described to me as having
been exceedingly fierce. I mention this because M. Temminck supposes
that the domesticated varieties of all animals are of larger size, than
the wild stock from which they are descended."—D.*

* I must refer the reader to my journal for some
account of the habits of the jaguar and puma, which being well known
animals, and the facts that I mention having little scientific
interest, I have not thought it worth while to repeat them here.

"This animal is not uncommon at Maldonado, where it is called
"Huron" or thief, from the ravages it commits on eggs and poultry.
Shortly after being killed this specimen weighed 1 lb. 8 oz. (Imp.
weight)."— D.

DESCRIPTION.—This Otter is about equal in size to the common
European species (Lutra vulgaris, Auct.): its fur is short,
glossy, and adpressed; the under fur is tolerably abundant and of a
silky nature. The general colouring of the ordinary fur is deep brown,
and that of the under fur is very pale brown, deeper externally. The
tint of the under parts of the body is paler than the upper, and may be
described as brown, that of the throat, sides and under part of the
neck, pale brown; and, on the tip of the muzzle and chin, dirty
yellowish-white. The hairs of the moustaches are brownish-white; the
ears are covered with short deep brown hairs, those towards the tip are
paler. The hairs covering the feet above are short, and of a very deep
brown colour. The tail is tolerably long, thick at the base, whence it
gradually tapers to the apex. The hairs on the base of the tail
resemble those of the body, but on the remaining portion, they are
short, glossy, and very closely applied to the skin both on the upper
and under surface, whereas those on the sides are longer, and form a
kind of fringe. The tip of the muzzle and the soles of the feet are
naked, with the exception of the hinder half of the tarsus.

The La Plata Otter in its general colouring is of a somewhat deeper
hue than the European species, the cheeks and throat instead of being
nearly white are of a pale brown colour; the tail is longer in
proportion, and tapers more gradually; the tip of the muzzle is naked,
but the hairless portion is less than in that species, the boundary
line between the naked part and the hair of the top of the muzzle
forming almost a semicircle; the retiring extremities of this line
touch the posterior angle of the nostril on each side, whereas in the
common otter the boundary line of the hair of the muzzle is of a w-like
form. The skull is figured in Plate 35, figs. 4, a, b,
c, and d, and is compared with that of L.
Chilensis in the next description.

"This specimen was killed by some fishermen a few miles from
Maldonado, near the mouth of the estuary of the Plata, where the water
is quite salt. I am not, however, by any means sure that it may not be
a fresh-water species, which had wandered from its proper station; in
the same manner as not unfrequently is the case with the Hydrochærus
Capybara. I am indebted to Mr. Chaffers, the master of the
Beagle, for having kindly presented me with this specimen."— D.

2. LUTRA CHILENSIS.

Lutra Chilensis, Bennett, Proceedings of the Committee of
Science and Correspondence of the Zoological Society of London for
1832, p. 1.

DESCRIPTION.—This species scarcely equals a full grown European
otter in size. It is of a brown colour throughout; the cheeks, chin,
and throat, being slightly paler, and the feet of a deeper tint, than
the other parts. The fur is moderately long, rather harsh to the touch,
and semi-erect: the under fur is abundant, and of a soft and silk
nature. The hairs of the ordinary fur are deep brown, but tipped with a
very pale brown colour. The hairs of the tail, like those of the body,
are harsh and semi-erect; towards the apex, those on the upper and
under part are in a slight degree shorter than those at the sides, and
lie closer to the skin; these differences, however, are not very
apparent on the upper side, though distinct on the under. The feet are
naked beneath, with the exception of the posterior half of the tarsus.
The hair of the muzzle extends only down to the posterior angle of the

nostrils, where it terminates in a straight line, leaving the tip of
the muzzle naked.

In.

Lines.

In.

Lines.

Length from nose to root of
tail . .

31

0

Length of tail . . . . .

14

3

Habitat, Chonos Archipelago, (January.)

The Chile Otter was originally described by Mr. Bennett from a
specimen presented to the Zoological Society by Mr. Cuming, but as this
specimen is a young animal, scarcely half-grown, it does not present
some of the characters of the species in so marked a manner as the
adult. I have, therefore, availed myself of an adult specimen in Mr.
Darwin's collection, to draw up the above description.

Compared with the Common Otter (Lutra vulgaris, Auct.) the
most striking difference consists in the character of the fur: the
hairs instead of being adpressed as in that species, are here
semi-erect, and appear as if they had been clipped at the extremity.
The fur is of a deeper colour, but has a slightly grizzled appearance,
owing to the tip of each hair being of a much paler colour than the
remaining part.

In the young animal described by Mr. Bennett, (which in weight was
probably not more than one-third of that of the present animal) the
hairs of the body are of an uniform deep brown colour; hence, if I am
right in considering Mr. Darwin's animal as the same species, it would
appear that the grizzled character of the fur is dependent on age.

The semi-erect fur will also serve to distinguish the present
species from the Lutra Platensis; the fur is likewise
longer, the tail is shorter, and the feet are smaller in proportion.
The most important distinctions, however, are furnished by the skulls;
I will, therefore, compare them.

The skull of L. Chilensis compared with that of L.
Platensis, (Plate 35, figs. 4.) when viewed from above, presents
but little difference in general form; it is, however, smaller in all
its proportions, and the zygomatic arch is a little less convex: the
palate is proportionately shorter; the tympanic bullæ are much smaller,
less elevated, and wider apart, in which respect there is a greater
approximation to the skull of L. vulgaris than to that of L.
Platensis; but here, the tympanic bullæ are larger than in L.
Chilensis. Both in L. Chilensis and Platensis,
the sub-orbital foramina are kidney-shaped, the emarginated portion
being downwards, whilst in L. vulgaris they approach
somewhat to a triangulur figure, the apex being external. In L.
Chilensis, however, this foramen is comparatively larger than in L.
Platensis, and the outer portion of the foramen forms the

segment of a larger circle than the inner one, whilst in L.
Platensis both portions are equal.

The principal difference in the dentition of the La Plata and the
Chile otters, consists in the comparatively smaller size of the
posterior molars, both of the upper and lower jaws, of the latter
species. In the upper jaw, the "carnassière" has its inner lobe,
approaching somewhat to a triangular form, whereas in L. Platensis
it is broader and almost semicircular. In the lower jaw, the last
molar but one has the inner lobe much smaller than the middle outer
lobe, whilst in L. Platensis these two lobes are of nearly
equal size and elevation. Other points of dissimilarity will be
perceived in the annexed table of admeasurements.

L. Chilensis.

L. Platensis.

In.

Lines.

In.

Lines.

Whole length of skull . . . .
. . . . . .

3

9¾

4

2½

Greatest width . . . . . . .
. . . .

2

6
1/3

2

10 1/3

Width of skull from the apex
of one mastoid process to the opposite . .

2

3¼

2

8¼

Length of palate . . . . . . . .
. . .

1

6

1

10

Breadth of palate between the
posterior molars . . . . . .

7¾

7¾

Length from last molar to
posterior margin of palate . . . . .

3 1/3

5½

from base of canine to hinder part of last molar . . . .

11 2/3

1

1 1/3

of carnassière . . . . . . . . . .

5

5 2/3

Width of do. . . . . . . . . . .

5

6¼

Length of last molar . . . . . .
. . . .

2¾

3½

Width of do. . . . .: . . . . . .

4 1/3

5 2/3

Length of ramus of lower jaw . .
. . . . . . .

2

4½

2

8¾

from canine to hinder portion of last molar (lower jaw) . .

1

2¼

1

4¼

of last molar but one (lower jaw) . . . . . .

5¾

6 2/3

Width of do. . . . . . . . . . .
.

2 2/3

3½

"These animals are exceedingly common amongst the innumerable
channels and bays, which form the Chonos Archipelago. They may
generally be seen quietly swimming, with their heads just out of water,
amidst the great entangled beds of kelp, which abound on this coast.
They burrow in the ground, within the forest, just above the rocky
shore, and I was told, that they sometimes roam about the woods. This
otter does not, by any means, live exclusively on fish. One was shot
whilst running to its hole with a large volute-shell in its mouth;
another (I believe the same species) was seen in Tierra del Fuego
devouring a cuttle fish. But in the Chonos Archipelago, perhaps the
chief food of this animal, as well as of the immense herds of great
seals, and flocks of terns and cormorants, is a red coloured crab
(belonging to the family Macrouri) of the size of a prawn, which swims
near the surface in such dense bodies, that the water appears of a red
colour. This specimen weighed nine pounds and a half."— D.

DESCRIPTION.—Upper parts of the body black, under parts pure white,
the two blended into each other by gray: extremity of snout, a ring
round the eye, the edge of the under lip, and the tail fin, black;
dorsal and pectoral fins dark gray; a broad gray mark extends from the
angle of the mouth to the pectoral fin; above which, the white runs
through the eye and is blended into gray over the eye; two broad
deep-gray bands are extended in an oblique manner along each side of
the body, running from the back downwards and backwards; iris of eye
dark brown. Body anteriorly somewhat depressed, posteriorly compressed;
head conical, arched above; the lower lip projecting beyond the upper;
eye placed above and behind, but near the angle of the mouth; breathing
vent situated in the same line as the eyes—supposing a circle to be
taken round the head. Teeth slightly curved, and conical; in the upper
jaw twenty-eight in number on each side, and in the lower, twenty-seven.

This species, which I have taken the liberty of naming after Captain
FitzRoy, the Commander of the Beagle, approaches in some respects to
the Delphinus superciliosus of the "Voyage de la Coquille,"
but that animal does not possess the oblique dark-gray bands on the
sides of the body; it likewise wants the gray mark which extends from
the angle of the mouth to the pectoral fins. In the figure the under
lip of the D. superciliosus is represented as almost white,
whereas in the present species it is black: judging from the figures,
there is likewise considerable difference in the form. The figure which
illustrates this description agrees with the dimensions, which were
carefully taken by Mr. Darwin immediately after the animal was
captured, and hence is correct.

"This porpoise, which was a female, was harpooned from the Beagle in
the Bay of St. Joseph, out of several, in a large troop, which were
sporting round the ship. I am indebted to Captain FitzRoy for having
made an excellent coloured drawing of it, when fresh killed, from which
the accompanying lithograph has been taken."—D.

FAMILY — CAMELIDÆ.

AUCHENIA LLAMA. Desmarest.

Guanaco of the aborigines of Chile.

"The Guanaco abounds over the whole of the temperate parts of South
America, from the wooded islands of Tierra del Fuego, through
Patagonia, the hilly parts of La Plata, Chile, even to the Cordillera
of Peru. I saw several of these animals in Navarin Island, forty miles
north of Cape Horn; the Guanaco, therefore, has, with the exception of
a fox and mouse, inhabitants of the same island, the most southern
range of all American quadrupeds. Although preferring an elevated site,
it yields in this respect to its near relative the Vicuña. On the
plains of Southern Patagonia, we saw them in greater numbers than in
any other part. Generally they go in small herds, from half a dozen to
thirty together; but on the banks of the Santa Cruz, we saw one herd,
which must have contained at least five hundred. On the northern shores
of the Strait of Magellan they are also very numerous. The Guanacoes
are generally wild and extremely wary: Mr. Stokes told me, that he one
day in Patagonia saw through a glass a herd of these beasts, which
evidently had been frightened, and were running away

at full speed, although their distance was so great that they could
not be distinguished by the naked eye.

"The sportsman frequently receives the first intimation of their
presence, by hearing from a long distance their peculiar shrill
neighing note of alarm. If he then looks attentively, he will, perhaps,
see the herd standing in a line on the side of some distant hill. On
approaching, a few more squeals are given, and then off they set, at an
apparently slow but really quick canter, along some narrow beaten track
to a neighbouring hill. If, however, by chance he should abruptly meet
a single animal, or several together, they will generally stand
motionless, and intently gaze at him; — then, perhaps, move on a few
yards, turn round, and look again. What is the cause of this difference
in their shiness ? Do they mistake a man in the distance for their
chief enemy the puma ? Or does curiosity overcome their timidity ? That
they are curious is certain, for if a person lies on the ground, and
plays strange antics, such as throwing up his feet in the air, they
will almost always approach by degrees to reconnoitre him. It is an
artifice that was repeatedly practised with success by the sportsman of
the Beagle, and it had moreover the advantage of allowing several shots
to be fired, which were all taken as parts of the performance. On the
mountains of Tierra del Fuego, and in other places, I have more than
once seen a Guanaco on being approached, not only neigh and squeal, but
prance and leap about in the most ridiculous manner, apparently in
defiance, as a challenge. These animals are very easily domesticated,
and I have seen some in this state near the houses in northern
Patagonia, although at large on their native plains. They are, when
thus kept, very bold, and readily attack a man, by striking him from
behind with both knees. It is asserted, that the motive for these
attacks is jealousy on account of their females. The wild Guanacoes,
however, have no idea of defence; and even a single dog will secure one
of these large animals, till the huntsman can come up. In many of their
habits they are like sheep in a flock. Thus when they see men
approaching in several directions on horseback, they soon become
bewildered, and know not which way to run. This circumstance greatly
facilitates the Indian method of hunting, for they are thus easily
driven to a central point, and are encompassed.

"The Guanacoes readily take to the water; several times at Port
Valdes they were seen swimming from island to island. Byron, in his
voyage, says he saw them drinking salt water. Some of our officers
likewise saw a herd apparently drinking the briny fluid from a Salina
near Cape Blanco; and in several parts of the country, if they do not
drink salt water, I believe they drink none at all. In the middle of
the day, they frequently roll in the dust, in saucer-shaped hollows.
The males often fight together; one day two passed quite close to me,
squealing and trying to bite each other; and several were shot with
their

hides deeply scored. Herds appear sometimes to set out on exploring
parties: at Bahia Blanca, where within thirty miles of the coast these
animals are extremely scarce, I one day saw the tracks of thirty or
forty, which had come in a direct line to a muddy salt water creek.
They then must have perceived, that they were approaching the sea, for
they had wheeled with the regularity of cavalry, and had returned back
in as straight a line, as they had advanced. The Guanacoes have one
singular habit, the motive of which is to me quite inexplicable,
namely, that on successive days they drop their dung on one defined
heap. I saw one of these heaps, which was eight feet in diameter, and
necessarily was composed of a large quantity. Frezier remarks on this
habit as common to the Guanaco as well as to the Llama; * he says it is
very useful to the Indians, who use the dung for fuel, and are thus
saved the trouble of collecting it.

"The Guanacoes appear to have favourite spots for dying in. On the
banks of the Santa Cruz, the ground was actually white with bones in
certain circumscribed spaces, which generally were bushy and all near
the river. On one such spot I counted between ten and twenty heads. I
particularly examined the bones; they did not appear, as some scattered
ones which I had seen, gnawed or broken as if dragged together by a
beast of prey. The animals in most cases, must have crawled, before
dying, beneath and amongst the bushes. Mr. Bynoe informs me, that
during the last voyage, he observed the same circumstances on the banks
of the Rio Gallegos. I do not at all understand the reason of this; but
I may add, that the Guanacoes which were wounded on the plains near the
Santa Cruz invariably walked towards the river. This quadruped seems
particularly liable to contain in its stomach bezoar stones. The
Indians who trade at the Rio Negro, bring great numbers to sell as
Remedios or quack medicines; and I saw one old man with a box quite
full of them, large and small."—D.

* D'Orbigny says, (vol. ii. p. 69,) that all the
species of the genus have this habit.

BESIDES skins of this species of stag, I find, in Mr. Darwin's
collection, three pairs of horns, which, together with a pair belonging
to one of the skins, constitute a sufficiently complete series to
illustrate the different forms which these appendages assume, as the
animal increases in size.

The above four sketches, which are all drawn to the same scale, will
help to convey a clear idea of the forms, and relative proportions, of
these horns.

The most simple horn (fig. 1.) consists of a beam, eight
and a half inches long, which is slightly arched outwards and
considerably compressed about two and a half inches from the apex. At
one inch from the base there is a small brow antler which projects
forwards and upwards.

In the next horn, (fig. 2.) there is the same small brow antler, but
there is a single small snag, about equal in size to the brow
antler, which is directed back-

* Figures 47 and 48 of M. Cuvier's work represent
horns so unlike either of those brought over by Mr. Darwin, that I
cannot help suspecting they belong to some other species of stag.

wards and upwards, and is situated at three and a quarter inches
from the apex of the beam. The total length of the beam is eight
inches, measured in a straight line.

The third pair of horns, (fig. 3.) which must have belonged to an
animal considerably older than either of the preceding pairs, exhibits
a large brow antler, in length exceeding half that of the beam: here
the posterior snag is also large, and is directed backwards and
upwards, whilst the apical portion of the beam is directed forward
about as much as the snag is directed backwards. The total length of
this horn is eleven and a half inches, measured in a straight line.

The last figure (No. 4.) represents the horn of one of the specimens
of which an entire skin was brought over. This horn differs only from
the last in being slightly larger, and in having two additional small
snags, one springing from the under side, and near the apex, of the
brow antler, and the other springing from the hinder part, and near the
apex of the great posterior snag.

"The Spaniards say they can distinguish how old a deer is by the
number of the branches on the horns. They affirmed that the specimen,
of which figure 4 represents one of the horns, was nine years old. It
certainly was a very old one, as all its teeth were decayed. This
specimen was killed at Maldonado, in the middle of June; another
specimen was killed at Bahia Blanca, (about three hundred and sixty
miles southward,) in the month of October, with the hairy skin on the
horns: there were others, however, whose horns were free from skin. At
this time of the year, many of the does had just kidded. I was
informed, by the Spaniards, that this deer sheds its horns every year.

"The Cervus campestris is exceedingly abundant throughout
the countries bordering the Plata. It is found in Northern Patagonia as
far south as the Rio Negro, (Lat. 41°); but, further southward, none
were seen by the officers employed in surveying the coast. It appears
to prefer a hilly country; I saw very many small herds, containing from
five to seven animals each, near the Sierra Ventana, and among the
hills north of Maldonado. If a person, crawling close along the ground,
slowly advances towards a herd, the deer frequently approach, out of
curiosity, to reconnoitre him. I have by this means killed, from one
spot, three out of the same herd. Although thus so tame and
inquisitive, yet, when approached on horseback, they are exceedingly
wary. In this country nobody goes on foot, and the deer knows man as
its enemy, only when he is mounted, and armed, with the bolas. At Bahia
Blanca, a recent establishment in Northern Patagonia, I was surprised
to find how little the deer cared for the noise of a gun: one day, I
fired ten times, from within eighty yards, at one animal, and it was
much more startled at the ball cutting up the ground, than at the
report.

"The most curious fact, with respect to this animal, is the
overpoweringly

strong and offensive odour which proceeds from the buck. It is quite
indescribable: several times, whilst skinning the specimen, which is
now mounted at the Zoological Museum, I was almost overcome by nausea.
I tied up the skin in a silk pocket-handkerchief, and so carried it
home: this handkerchief, after being well washed, I continually used,
and it was, of course, as repeatedly washed; yet every time, when first
unfolded, for a space of one year and seven months, I distinctly
perceived the odour. This appears an astonishing instance of the
permanence of some matter, which in its nature, nevertheless, must be
most subtile and volatile. Frequently, when passing at the distance of
half a mile to leeward of a herd, I have perceived the whole air
tainted with the effluvium. I believe the smell from the buck is most
powerful at the period when its horns are perfect, or free from the
hairy skin. When in this state the meat is, of course, quite uneatable;
but the Spaniards assert, that if buried for some time in fresh earth,
the taint is removed. These deer generally weigh about sixty or seventy
pounds."—D.

FAMILY — MURIDÆ.

1. MUS DECUMANUS.

Mus decumanus, Auctorum.

IN the extensive collection of Rodent animals brought home by Mr.
Darwin, I find several specimens of the above named species, that is to
say, animals which resemble the European specimens of Mus
Decumanus in all those characters which are the least liable to
variation in individuals of the same species, such as the proportions
which the various parts of the animal bear to each other: they differ,
however, somewhat in colouring.

Buenos Ayres, Maldonado, Valparaiso, East Falkland Island, and
Keeling Island, are each, it appears, infested with the common European
rat. I have now before me two specimens from East Falkland Island, and
one specimen from each of the other localities, and among these I find
none equal in size to the largest European specimens: as regards the
colouring, the Buenos Ayres specimen differs only from the English
specimens of Mus Decumanus, in having the upper parts of a
richer and deeper hue, owing to the tips of the shorter hairs being of
a deep yellow instead of pale yellow, and in having a rusty tint over
the haunches.

Mr. Darwin found this variety "common about houses in the country
around Buenos Ayres."

In the Maldonado variety, the shorter hairs of the upper parts of
the body are of a rusty yellow colour at the apex, in other respects it
resembles the British variety. The rusty yellow colour of the tips of
the hairs produces a general reddish hue, which is the more
conspicuous, when the animal is placed near an English specimen. "Was
caught in a house, at Maldonado. I saw a specimen of the common gray
English, or Norway rat, lying dead in the streets, and it certainly had
a very different appearance from these red rats. The latter, I saw
crawling about the hedges in the interior provinces at Santa Fé, and
likewise in the forest of the island of Chiloe. This latter fact,
however, is a strong argument against its being aboriginal, since I did
not find even one undoubted American species, out of the many which I
collected, inhabiting both sides of the Cordillera." — D.

The specimen from Valparaiso very closely resembles that from
Maldonado; it is, perhaps, a little less red. "Common about the houses
in the town of Valparaiso."

The two specimens from East Falkland are of a brighter hue, and have
less gray in their colouring, than in the European variety of the
common rat. "One of them was caught in a Bay, which is sometimes
frequented by shipping, but which is distant thirty or forty miles from
any habitation. These rats have spread, not only over the whole of East
and West Falkland, but even on some of the outlying islets. When the
cold, wet, and gloomy nature of the climate is considered, it is
surprising that these animals should be able to find food to live on."—
D.

The general hue of the Keeling Island specimen, is deep brown, the
longer hairs of the upper parts of the body being, as usual, black; but
the shorter hairs, instead of having the pale yellow tint which we
observe in the European, (or, rather, British) specimens of Mus
Decumanus, are of a deep, rusty yellow. The most remarkable
difference, however, consists in the colouring of the under parts being
of a yellowish tint, and, towards the root of the tail, of a very
distinct buff yellow: the feet are brownish.

"This rat is exceedingly numerous on some of the low coral islets
forming the margin of the Lagoon of Keeling Island, in the Indian
Ocean. The climate is dry and hot. The rats are known to have come in a
vessel from the Mauritius, which was wrecked on one of the islets,
which is now called Rat Island. They appeared stunted in their growth,
and many of them were mangy. They are supposed to live chiefly on
cocoa-nuts, and any animal matter the sea may chance to throw up. They
have not any fresh-water; but the milk of the cocoa-nut would supply
its place."—D.

Upon comparing the skull of the Valparaiso variety with that of a
British specimen of Mus decumanus, I could perceive no
difference. A skull from West Falkland did not differ, neither did the
dentition of the Keeling Island specimen above noticed. A perfect
specimen of this last I have not had an opportunity of examining.

2. MUS (DECUMANUS var. ?) MAURUS.

Mus maurus, Waterh. in Proceedings of the Zoological
Society of London, for February, 1837, p. 20.

DESCRIPTION.—The character of the fur of this animal nearly
resembles that of Mus decumanus; it is, however, of a
harsher nature: the general colour of the upper parts and sides of the
body is purple-black, arising from the longest hairs being of this
colour, and likewise the tips of those which are next in length; the
latter, however, excepting at the tip, are white, and this white is not
entirely hidden, even when the hairs are in their ordinary position:
on the head the hairs assume a brownish hue, and are tolerably uniform:
the limbs, and under parts of the body, are of a deep gray colour,
with a faint purple-brown wash: the under fur is gray: the ears are
small, of a brown-white, or very pale brown colour, and furnished with
minute brown hairs: the small, scattered, bristly hairs of the tail are
of an uniform brownish-black colour. The hairs of the moustaches are
black at the base, and grayish at the apex.

This rat is very closely allied to Mus decumanus, and I
think may possibly prove an extraordinary local variety of that animal.
Having but one skin, and no skull, I am unable to satisfy myself on
this point. Its size, as will be seen by the admeasurements, exceeds
that of the common rat, or, rather, it exceeds ordinary specimens of
that animal, for I have seen some which were equal to it.

"It was killed near Maldonado, where it frequented holes in the sand
hillocks near the shore. It is likewise found on the island of Guritti.
If ships are ever infested with these monstrous rats, the
above-mentioned localities are very likely places to have received
colonies by such means. An old male weighed fifteen ounces and three
quarters. The ears of this rat, when alive, were of a pale colour,
which made a singular contrast with the black fur of its body."—D.

3. MUS JACOBIÆ.

Mus decumanoïdes,* Waterh. in "Catalogue of the Mammalia
preserved in the Museum of the Zoological Society of London."

DESCRIPTION.—The general tint of the upper parts of this rat, is
grayish-brown, (very nearly resembling that of Mus decumanus);
the longest hairs, which on the hinder portion of the back are one
inch and a half in length, are black; the ordinary hairs are black at
the apex, there is then, on each hair, a considerable space occupied by
pale yellow, and the remaining, or basal portion, is grayish white; the
under fur is gray: the hairs of the chin, throat, and under parts of
the body, are white, and without any gray colour at the roots: the feet
are covered with dirty grayish hairs: the tail, which is slender, is
very sparingly furnished with minute black hairs, both above and
beneath: the ears are of moderate size, of a brownish flesh colour,
and, to the naked eye, appear to be destitute of hair. The hairs of the
moustaches are most of them black at the base, and grayish at the apex.

* The MS. name of M. decumanoïdes, which I
had applied to this animal, has been changed, in consequence of my
having seen a different species, with the same name attached, in the
museum of the India House.

This species is scarcely equal in size to a full grown common black
rat, (Mus Rattus), the head is rather shorter in proportion,
the tarsi are smaller, and the tail is longer. In the character of the
fur, and length of the hairs, it very closely resembles that
species: the ears are larger than in M. decumanus, and about
equal to those of M. Rattus. In having the hairs of the
under parts of the body of an uniform colour, (i. e. not gray at the
base,) it resembles the Mus Tectorum of Savi; but the large
size of that animal, the greater length of the fur, and its colouring,
all serve to distinguish it from the present species, which I may here
observe, is truly an old world form, and very distinct from another
species, also from the Galapagos, which is hereafter described.

"It is very common in James Island, but is not found on all the
islands, if on any other in the Archipelago. Although its appearance is
so like that of the common rat, yet its habits appear to be rather
different: it is less carnivorous, and does not appear to be so
strongly attached to the habitations of man. This island was
frequented, about one hundred and fifty years since, by the vessels
belonging to the Bucaniers; so that the common rat might easily have
been transported here. And if a very peculiar climate, a volcanic soil,
and strange food, can together produce a race, or strongly marked
variety, there is every probability of such change having taken place
in this case."—D.

DESCRIPTION.—No. 1. The general colour of this animal is what might
be termed black, there is, however, an obscure purple-brown hue on the
upper parts of the body, and the sides and under parts have a grayish
tint, the hairs covering the feet above are of an uniform deep
purple-brown, almost black. All the hairs of the body are gray at the
base: the hairs of the moustaches are long and numerous, and of a black
colour, having one or two white hairs intermixed: the ears are of
moderate size, and very sparingly furnished with

minute dark hairs: the tail is long and slender, and has small,
scattered, bristly hairs, of a brown-black colour.

In.

Lines.

In.

Lines.

Length

from nose to root of tail . .

7

0

Length of ear . . . . .

0

7

of tail . . . .
. .

6

6

from nose to ear
. . . .

1

6

of tarsus . . . . . .

1

3½

No. 2. Hairs along the centre of the back chiefly black, and but
obscurely annulated, near the apex, with deep yellow: towards the sides
of the body, and over the haunches, the hairs are more distinctly
annulated, and on the sides of the body they are of a pale yellow at
the apex: on the under parts the hairs are gray, tipped with dirty
yellowish white: the feet are of the same deep purple-brown hue as in
the specimen first described.

Habitat, Ascension Island, Atlantic Ocean, (July.)

These two animals not only differ in the colour of the fur, one
being of a grizzled brownish colour, and the other black, but there is
a considerable difference in the texture of the fur. In the black
specimen, the fur is very soft and glossy, and the long hairs, which
are abundant, are very slender. In the brown specimen, the fur is of a
harsher nature, the long hairs are not so abundant, but longer, and
less slender. On the other hand, they agree in size, dentition, the
length of the head, tarsus, and ears, and differ but in a trifling
degree (about three lines,) in the length of the tail.

Upon comparing the Ascension Island specimens with M. Rattus,
I find that, although in size they are about one third less, yet the
teeth precisely agree, not only in form, but in size. The relative
proportions of the head, ears, and tarsi, also agree. Besides the
general colouring of the fur, they both differ in having the hairs of
the feet uniformly purple-black, those in Mus Rattus being
much paler, and even whitish, on the toes. In the character of the fur,
there is much difference. The long silky hairs, which are so
conspicuous in Mus Rattus, are replaced, in the black
specimen, by hairs which are scarcely to be distinguished from the
ordinary fur; and in the other specimen, although rather longer and
more distinct, they are short, compared with those of the black rat.

" The specimen which has a black, and glossy fur, frequents the
short coarse grass near the summit of the island, where the common
mouse likewise occurs. It is often seen running about by day, and was
found in numbers, when the island was first colonized by the English, a
few years since. The other, and browner coloured variety, lives in the
out-houses near the sea-beach, and feeds

chiefly on the offal of the turtles, slaughtered for the daily food
of the inhabitants. If the settlement were destroyed, I feel no doubt
that this latter variety would be compelled to migrate from the coast.
Did it originally descend from the summit ? and, in the case just
supposed, would it retreat there ? and, if so, would its black colour
return ? It must, however, be observed, that the two localities are
separated from each other by a space, some miles in width, of bare lava
and ashes. Does the summit of Ascension, an island so immensely remote
from any continent, and the summit itself surrounded by a broad fringe
of desert volcanic soil, possess a small quadruped, peculiar to itself?
Or, more probably, has this new species been brought, by some ship,
from some unknown quarter of the world? Or, I am again tempted to ask,
as I did in the case of the Galapagos rat, has the common English
species been changed, by its new habitation, into a strongly marked
variety?"— D.

Mr. Darwin seems to have foreseen the difficult problem which these
two rats have furnished, and although I have spent much time in
studying the Muridæ, I must confess I have been exceedingly puzzled by
the animals in question. It appears as if the brown, and black rats, (M.
decumanus, and M. Rattus,) and likewise the common
mouse, (M. Musculus,)* all of which follow man in his
peregrinations, and which, to a certain degree, are dependent upon man,
and may therefore be termed semi-domestic animals; like really domestic
animals, are subject to a greater degree of variation than those
species which hold themselves aloof from him.

Upon the whole then I have determined to describe the two Ascension
Island specimens as one species, and as varieties of the Mus Rattus,
but with a mark of doubt, since I do not possess sufficient materials
for a rigorous examination, having, in fact, but one skin of each
variety, and neither skull nor skeleton. I have also applied the name
of insularis, to designate this variety or species, whichever
it may be, for, supposing it be not a distinct species, it is so marked
a variety, that a name for it is desirable.

* The great Bandicoot rat of India, (Mus giganteus,
of Hardwicke,) ought, perhaps, to be added to the species above
enumerated; and I strongly suspect several catalogued species will
prove but varieties of this animal.

Of this species, there are six specimens in Mr. Darwin's collection;
two were found "living in the short grass, near the summit of the
Island of Ascension, where the climate is temperate."—D. Two others
were procured "on a small, stony, and arid island, near Porto Praya,
the capital of St. Jago, in the Cape de Verde Islands,—climate very hot
and dry. Excepting during the rainy season, which is of short duration,
these little animals can never taste fresh water, nor does the island
afford any succulent plant."—D. A specimen was also procured "on a
grassy cliff, on East Falkland Island, at the distance of a mile from
any habitation. It is singular that so delicate an animal should be
able to subsist under the cold, and extremely humid climate, of the
Falkland Islands, and on its unproductive soil."—D. These specimens are
all of them rather less than full grown individuals of the same species
procured in England; in other respects, they do not differ.

The sixth specimen, which is from Maldonado, is considerably less
than British specimens of the common mouse, and is of a richer and
brighter colour, the head is smaller, the muzzle shorter in proportion,
whilst the tarsi are even longer than in a large specimen of M.
Musculus. These points of dissimilarity induced me to believe it
was a distinct species, and to apply to it the specific name of brevirostris.*
Upon re-examination, with the advantage of more experience, and
consequently a better knowledge of the characters of these animals, I
have changed my opinion. The teeth indicate that it is not an adult
specimen, and agree perfectly with those of M. Musculus, both
in form and size. "Common in the houses of the town of Maldonado, and
its habits are similar to those of Mus Musculus."—D.

* See Proceedings of the Zoological Society for
February 14th, 1837, p. 19.

DESCRIPTION.—Fur long and soft; general colour pale yellow-brown,
the hairs of the ordinary fur being fulvous near the apex, and the
longer hairs brown. On the sides of the body, cheeks, and external side
of limbs, the fulvous hue prevails. The inner side of the limbs and the
under parts of the body are white, but have an indistinct yellowish
hue. All the hairs of the body are of a deep gray colour at the base.
The ears are small, well clothed with hairs; those on the inner side
are chiefly yellow; externally, on the fore part they are brown, and
posteriorly whitish. The feet are of a flesh-colour, and furnished
above with white hairs; the tarsi are but sparingly provided with
minute hairs on the upper side, and are naked beneath: they are of
unusually large size. The fore feet are of moderate * size, and
furnished with a very large carpal tubercle. The tail is very nearly
double the length of the body, if the latter be measured in a straight
line; it is of a brownish flesh-colour above, paler beneath, and
sparingly furnished with minute bristly hairs; those on the upper
surface being brown, and on the under side white. The hairs of the
moustaches are long, of a black colour, and grayish at the apex.

In.

Lines.

In.

Lines.

Length

from nose to root of tail . .

3

9

Length of tarsus (claws
included) . .

1

1

of tail . . . .
. .

5

3

of ear
. . . .

0

4

from nose to ear . . .

0

10½

Habitat, Chile.

* As I shall have occasion to use the terms moderate,
long, short, large, &c. it may be well to state that I take
the common mouse, (Mus Musculus,) as my standard of
comparison. The ears, feet, tail, length of the fur, general
proportions, &c. are in that animal what I term moderate.

The most conspicuous characters of the present species consist in
the immense length of the tail, and the great size of the hinder feet.
* It is about equal in size to Mus Musculus; its form,
however, is somewhat stouter; in colour it is much paler and brighter.
The head is larger in proportion; the ears are smaller, and more
densely clothed with hair; the fore feet are rather larger, and the
fleshy tubercle on the under side of the wrist is also larger. The
thumb nail is flattened, and rounded at the tip, as in Mus Musculus,
but is longer, and more distinct than in that animal.

The skull of M. longicaudatus, (Plate 34, Fig. 1,) is
considerably larger than that of the common mouse, but in form scarcely
differs from it; its upper surface is rather more convex, and the
interparietal bone proportionately less. The length of the skull is 1
inch; breadth, 6½ lines; distance between the fore part of the incisor,
and the first molar of the upper jaw, 3½ lines. The dentition is
figured in Plate 34, Figs. 1. b and 1. c.

The above account is drawn up from the same specimen as that from
which Mr. Bennett took his description, and which was brought from
Chile by Mr. Cuming, who states that the animal in question lives in
trees, and constructs its nest with grass.

In Mr. Darwin's collection, I find an animal which agrees in all the
more important characters with the one above described, but differs in
being of a deeper colour, (approaching more nearly, in this respect, to
the common mouse,) and in having the tail a trifle shorter. The skull
is about ¾ of a line shorter, but its proportions agree precisely: the
proportions of the feet, and the general form of the animal, also
agree. This specimen is likewise from Chile, (Lat 37° 40',) and,
according to Mr. Darwin, "overran the wooded country south of
Concepcion, in swarms of infinite numbers. Captain FitzRoy, on his
return from visiting the wreck of H. M. S. Challenger, had the kindness
to bring me this specimen. So destructive was this little animal, that
it even gnawed through the paper of the cartridges belonging to the
people who were wrecked."—D.

* A long tarsus is generally accompanied by a
proportionately long tail. I presume that those Mice which have long
tarsi are in the habit of making great leaps, and that in these leaps,
the tail serves to steady and balance the body.

DESCRIPTION.—Fur very long and soft; general colour of the upper
parts of the body pale brownish yellow; the lower portion of the
cheeks, and the under parts of the body pure white: the hairs of the
ordinary fur of the back are gray at the base, pale ochre near the
apex, and brown at the apex; the longer hairs are brownish. On the
sides of the body where the longer hairs are less numerous, the pale
ochre colour prevails; the hairs on this part as on the back are deep
gray at the base, but at a short distance from the apex they are white;
nearer the tip shaded into yellow, and at the tip brownish: the limbs
externally are of a pale yellow colour. The hairs of the throat and
chest are pure white to the root, those on the belly are obscurely
tinted with gray at the root. The feet are of a pale flesh-colour, and
furnished with white hairs; the fore feet are of moderate size; the
thumb nail is small and rounded, and the carpal tubercle is covered
with hairs; the tarsi are long, and the white hairs extend over the
whole of the under parts; the under side of the toes, however, are but
sparingly furnished. There appears to be but one large tubercle on the
under side of the tarsus, and this, which is situated near the base of
the toes, is thickly covered with silvery-white hairs. The tail is
long, pale brown above, and pale flesh-colour beneath; above, it is
furnished with minute brown hairs, and on the under side with white
hairs. The ears are rather large, of a pale flesh colour, tolerably
well clothed with hairs, which are of a pale yellow colour on the inner
side, and white on the outer side—excepting on the fore part, where
they are brown. A small tuft of white hairs springs from the base of
the ear posteriorly. The hairs of the moustaches are moderate; black at
the base, and grayish at the apex.

Upon comparing the skull (Pl. 34, fig. 2, a.) of M.
elegans with that of M. Musculus, the most evident
points of distinction consist in the greater proportionate length of
the nasal and frontal bones, and the slenderness of the zygomatic arch
in the former animal. Length of skull 11 lines, width 6 lines, distance
between front molar and outer side of incisors of upper jaw 33/8
lines, length of nasal bones 43/8 lines.

The dentition is figured in Pl. 34, figs. 2. b, and 2. c.

"Whilst bivouacking one night on shore, amongst some sand hillocks,
this mouse, with its tail singed, leapt out of a bush which was placed
on the fire. Its hind legs appeared long in proportion to the front,
and it did not appear to be very active in endeavouring to make its
escape."—D.

Mus elegans is about equal in size to M. Musculus; the
head is larger in proportion than in the latter, the ears are slightly
larger, the tail is longer, and so are the tarsi. The large ears, long
tail, and comparatively large size of the feet, combined with the
greater size of the animal itself, will render it easy to distinguish
this species from M. gracilipes and M. bimaculatus. From
the last mentioned animal it moreover differs in having the head larger
in proportion, the fur longer, and the colouring of the upper parts of
the body somewhat darker. The white fur is almost confined to the under
parts of the body, and there is but a small tuft of white hairs behind
the ears, whereas in M. bimaculatus, the white fur extends
considerably on the sides of the body, the outer side of the limbs are
white, and there is a large and conspicuous white spot behind each ear.

In M. elegans the whole sole of the tarsus and the carpal
tubercles are covered with hair. In Mus bimaculatus the
hinder half of the tarsus only is covered with hair, and in M.
gracilipes both the hinder half is covered, and there are some
scattered hairs extending almost to the two tubercles, which are
situated at the base of the longer toes.

The genus Eligmodontia of M. F. Cuvier, founded upon a
species of mouse from Buenos Ayres, possesses nearly the same
characters as the subgenus Calomys, established by me in the
Proceedings of the Zoological Society for February 1837, and which
included the animal above described, and two other species (M.
bimaculatus and M. gracilipes). M. Cuvier's genus is
distinguished by there being only one large tubercle on the under side
of the tarsus, and in having the carpal pad covered with hair as well
as the pad of the tarsus. In

these characters our present animal agrees, as it does also in size
and in the relative proportions of the tail and tarsus, circumstances
which induce me to believe they are identical.

In M. bimaculatus and M. gracilipes there are
six naked tubercles on the under side of the tarsus, and the carpal pad
is also naked. In having, however, the tarsus hairy beneath,* in
dentition and in colouring, they agree so closely with M. elegans that
I think they cannot be separated generically.

MUS BIMACULATUS.

PLATE XII.

Mus bimaculatus, Waterh., Proceedings of the Zoological
Society of London for February 1837, p. 18.

DESCRIPTION.—Upper parts of the body of a very pale ochre colour,
the longer hairs, however, are black, and at the apex grayish, and
where they are numerous, as on the back and upper surface of the head,
they give greater depth to the colouring; the cheeks and sides of the
body are of an almost uniform pale, but bright yellow; the sides of the
muzzle, the lower half of the cheeks, the lower portion also of the
sides of the body, and the whole of the under parts, are pure white —
each hair being uniform in colour to the root, and not, as is usually
the case, gray at the root. There is likewise a large patch
of pure white hairs behind each ear. The feet and tail are of a pale
flesh-colour, and furnished with white hairs, with the exception of
those on the upper surface of the latter, which are pale brown. The
ears are also pale flesh-colour, clothed internally with yellow hairs;
externally on the fore part, the hairs are brownish, and on the hinder
part, white—they are rather large, and so are the feet. The tail is
about equal to the body in length. The hairs of the moustaches are
numerous and slender, and most of them are black at the base, and gray
at the apex. The hinder half of the tarsus

* In Mus leucopus of North America the
tarsus is hairy beneath, and in the character of the teeth this animal
also agrees with the species above mentioned.

beneath is covered with minute silvery-white hairs; beside the
ordinary tubercles, the anterior portion of the sole of the foot and
the base of the toes beneath, are crowded with small rounded warts,
which are much more numerous and conspicuous than in the common mouse.

In.

Lines.

In.

Lines.

Length

from nose to root of tail . .

3

1

Length from nose to base of
ear . .

0

8¾

of tail . . . .
. .

1

11

of tarsus (claws
included) . .

0

8

from nose to eye . . .

0

4½

of ear . . . . .

0

4½

Habitat, Maldonado, La Plata, (June.)

The skull of this animal, is rather shorter and broader than that of
Mus Musculus, the upper surface is more arched, the zygomatic
arch is much more slender, and the nasal bones are rather broader. In
the convexity of the upper surface, and the slenderness of the
zygomatic arch, this skull very nearly resembles that of M.
gracilipes; this latter, however, has the zygomatic arch more
convex, projecting more suddenly on the anterior part, and the
interparietal bone smaller. Length of skull 10 lines, width 5½, length
of nasal bones 4 lines, distance between the outer side of the
incisors, of the upper jaw, and the first molar 27/8
lines. See Plate 34, fig. 3. a.

The dentition is figured in Plate 34, figs. 3. b and c.

This mouse is rather less than M. Musculus, the tail is
much shorter in proportion, the fur is longer and softer, and the ears
are more distinctly clothed with hair.

The pale and delicate yellow colour of the upper parts of the body,
and the pure white of the under parts, renders the present species
conspicuous amongst its congeners. I may further remark that the white
colour which in the Muridæ (when it occurs) is usually confined to the
under part of the body, or extends but slightly on the sides, is in the
present animal extended considerably on the sides of the body, and
occupies an equal portion with the yellow of the upper parts. The name bimaculatus
is applied to this animal on account of the two conspicuous white
patches, which are situated behind the ears.

In affinity as well as in appearance it most nearly approaches to Mus
gracilipes and M. elegans; with no other species of
the genus Mus, here described, can it be confounded, since these only
have the tarsus hairy beneath.

The principal points of distinction between the present animal and Mus
elegans, are noticed in the account of that species.

"This mouse, when alive, had a very elegant appearance. A
countryman, who brought it me, found six of them living together in one
burrow."—D.

DESCRIPTION.—General colour very pale yellowish brown, a tint
produced by the admixture of black and pale fawn colour; the hairs of
the ordinary fur being of the latter tint near the apex, and dusky at
the apex, whilst the longer hairs are black. The feet, tail, under
parts of the body and the sides of the muzzle, are pure white. All the
hairs of the body, (which are soft, and of moderate length), are deep
gray at the base. The ears are of moderate size, well clothed with
hairs, of which those on the inner side are yellowish, and those on the
outer, are brown on the anterior part, and white on the posterior. A
small tuft of white hairs springs from the neck immediately behind the
ears; this tuft is hidden when the ears are folded back. The tail is
slender and short, (being not quite equal to the body in length) of a
pale flesh-colour, and sparingly furnished with minute white hairs. The
feet are very small and slender, and the naked parts are of a pale
flesh-colour. The sole of the foot is covered with hairs; the toes
beneath, and the tubercles (which are as in Mus Musculus),
however, are naked. The hairs of the moustaches are of moderate length,
and of a blackish colour, some of them, however, are grayish white.

In.

Lines.

In.

Lines.

Length

from nose to root of tail . .

2

10

Length from nose to ear . .

0

8¼

of tail . . . .
. .

1

7

of tarsus (claws
included) . .

0

6½

from nose to eye . . .

0

41/3

of ear . . . . .

0

4¼

Habitat, Bahia Blanca, (September.)

This species slightly exceeds the harvest mouse (Mus messorius)
in size, its ears are considerably larger in proportion, and the tail
is shorter. Compared with the common mouse (Mus Musculus) it
is smaller, the tail is more slender, and shorter, and the feet are
likewise more slender and proportionately much smaller; the ears are
more distinctly clothed with hairs.

The principal points of distinction between this and the two
preceding species are pointed out in the account of M. elegans.

Upon comparing the skull of M. gracilipes (Pl. 34, fig.
4. a.) with that of Mus Musculus, the most striking
differences consist in its shorter and broader form, the upper surface
being more arched, the interparietal bone has a relatively smaller
antero-posterior diameter, the occipital region is more convex, and
continued more gently and gradually into the upper region of the skull.
The zygomatic arch, which is unusually slender, is more dilated
(especially on the anterior part) thus giving a squareness to the
general form. The nasal bones are not so much attenuated posteriorly.
The length of the skull is 87/8 lines, the
greatest width is 51/8 lines, and the distance
between the outer side of the incisors and the front molar is 2¾ lines.

The dentition is figured in Plate 34, figs. 4. b and 4. c.

"This specimen was given me by Mr. Bynoe, the surgeon of the
Beagle, who caught it amongst some long dry grass."—D.

MUS FLAVESCENS.

PLATE XIII

Mus flavescens, Waterh., Proceedings of the Zoological
Society of London, for February 1837, p. 19.

DESCRIPTION.—Fur long and moderately soft; general colour of the
upper parts bright brownish yellow; on the sides of the head and body
bright yellow; towards the rump of a deeper hue, and inclining to
orange; under parts pale yellow, or yellow-white; chest yellow. The fur
both of the upper and under parts of the body deep plumbeous at the
base. Feet flesh colour, covered above with white hairs: tarsi long,
naked beneath. Ears small, tolerably well clothed with hairs; those on
the inner side yellow, but many of them blackish at the base; on the
outer side, the hairs are blackish on the fore part and yellow on the
hinder part. The hairs of the ordinary fur of the back are of a deep
rich yellow colour at the tip, and the longer hairs are blackish. The
tail is long, deep brown above and whitish beneath; the hairs of the

moustaches are rather short and slender, and of a brownish colour.
Thumb nail small and rounded.

In.

Lines.

In.

Lines.

Length

from nose to root of tail . .

3

9

Length of tarsus . . . .

1

0½

of tail . . . .
. .

4

1½

of ear . . . . .

0

4½

from nose to ear . . .

1

0

Habitat, Maldonado, La Plata, (June.)

This species is slightly larger than the common mouse; the head is
rather larger in proportion; the ears are rather smaller and more
distinctly clothed with hair; the tail and tarsi are much longer in
proportion. Its bright yellow colouring and proportions distinguish it
from any of the species described in this work. Of this animal I do not
possess the skull, nor of the teeth do I possess more than the first
and second molars of the upper jaw, and the second and last of the
lower jaw. These are figured in Plate 34, figs. 5. a, and 5. b.

MUS MAGELLANICUS.

PLATE XIV.

Mus Magellanicus, Bennett, Proceedings of the Zoological
Society of London for December 1835, p. 191.

DESCRIPTION.—Fur very long and moderately soft, general colour deep
brown; the hairs of the ordinary fur are gray, tipped with yellowish
brown; the longer hairs are black; the sides of the body are yellowish;
the under parts are gray-white with a faint yellowish tint, each hair
being gray tipped with yellowish white. The ears are rather small, well
clothed with hairs; those on the inner side are blackish tipped with
yellow, and on the outer side they are blackish on the fore part and
dusky on the hinder part. The fore feet are of moderate size, the thumb
nail is short and rounded; the tarsi are rather long; both fore and
hinder feet are of a brownish colour, and covered above with dirty gray
hairs. The tail rather exceeds the head and body in length; it is
brown above and dirty white beneath. The hairs of the moustaches are
numerous and long, of a brownish colour at the apex and black at the
base.

This mouse is larger than Mus Musculus; the tail is
rather longer in proportion; the tarsi much longer; the ears are not
quite so large in proportion to the head, (which greatly exceeds that
of Mus Musculus in size,) and they are densely clothed with
hair. The fur is longer. In colour, the animal here described is rather
darker than the common mouse. I have one specimen however before me
which very nearly agrees in this respect.

The dentition is figured in Plate 34, figs. 6, a. and 6, b.

From the attention which Mr. Darwin bestowed upon the Muridæ of the
southern parts of South America, I presume his collection affords
materials for a tolerably complete monograph of the species of that
portion of the globe. The species above described, however, does not
occur in Mr. Darwin's collection, but is here introduced in order to
make the work more complete, and that I might more clearly point out
the distinctions which exist between it and other species here
described, the account given by Mr. Bennett in the Proceedings being
very short.

MUS ARENICOLA.

PLATE XIII.

Mus arenicola, Waterh., Proceedings of the Zoological
Society of London, for February 1837, p. 18.

DESCRIPTION.—Fur long, moderately soft; general colour deep brown;
sides of the body with a very obscure yellowish hue; under parts dirty
gray with a faint yellow tint. All the fur deep gray at the base; the
hairs of the upper part of the body obscurely annulated with yellowish
brown near the apex, and dusky at the apex; the longer hairs are black.
Feet brownish, covered above with brown-white hairs; tarsi short. Tail
short, blackish above, brown-white beneath. Ears small, well clothed
with hairs; those on the

inner side are yellow at the apex and
gray at the base; on the outer side they are of a brownish colour, and
on the fore part blackish. The hairs of the moustaches are short and
slender, and of a brownish colour. The head is large.

In.

Lines.

In.

Lines.

Length

from nose to root of tail . .

4

3

Length of tarsus (claws
included) . . . .

0

10

of tail . . . .
. .

2

9

of ear . . . . .

0

4½

from nose to ear . . .

1

0

Habitat, Maldonado, La Plata, (June.)

This species is rather larger than the
common mouse; its head is proportionately larger, the ears are
smaller, the tail considerably shorter, and the fur longer, and in
colouring it is a little darker. In size and colour it resembles M.
Magellanicus, but the shorter tail and tarsi, and the smaller
size of
the ears will serve to distinguish it.

The skull of Mus arenicola,
Plate 34.
fig. 7, a, is rather larger than that of Mus Musculus,
the
nasal
portion is broader, the interparietal bone is much smaller, especially
in antero-posterior extent; the zygomatic arches are more slender, and
the incisive foramina are broader. The horizontal ramus of the lower
jaw (Pl. 34. fig. 7, d.) is
rather less curved, the coronoid process is
more elongated, and the condyloid is narrower and also larger. The
length of the skull is 11 lines and a half; the width is 6 1/5 lines.
The
molars of the upper jaw are figured in plate 34 fig. 7, b.
and those of
the under jaw, fig. 7, c.

"This specimen was caught on the open
grassy plain, by a trap baited with a piece of bird; it is, however,
very abundant in the sand hillocks near the coast of the Plata."—D.

13. MUS BRACHIOTIS.

PLATE XIV.

Mus brachiotis, Waterh.,
Proceedings of the Zoological Society of London for February 1837, p.
17.

a deep gray at the base, black at the
apex, and narrowly annulated with deep yellow near the apex; on the
throat and belly they are of a paler gray at the base, and grayish
white at the apex. The ears are well clothed with brown hairs both
within and without, and are for the most part hidden by the long fur of
the head. The hairs covering the upper side of the feet are of a palish
ashy-brown colour, and the fleshy portion appears to have been brown.
The tail is well clothed with hairs, so that the scales are scarcely
visible; on the upper side of the tail the hairs are brownish-black,
and on the under side, they are dirty white. The incisors are very
slender; those of the upper jaw are of a very pale yellow colour, and
those of the lower are white, or nearly so. The muzzle is slender, and
pointed.

In.

Lines.

In.

Lines.

Length

from nose to root of tail . .

4

9

Length of tarsus (claws
included) . . . .

0

11

of tail . . . .
. .

2

8

of ear . . . . .

0

3

from nose to base of ears . .

1

2

Habitat, Chonos Archipelago, (December.)

This mouse is considerably larger than
Mus Musculus, and the great
length and density of its fur, causes it to
appear much stouter in its proportions; its colouring is darker, the
tips of the hairs being much more narrowly annulated with yellow than
in that species. The very small size of the ears will serve to
distinguish the present animal from its congeners—Mus longipilis,
M.
Renggeri, M. arenicola,
&c.

The molar teeth of the upper jaw are
figured in Plate 34. fig. 8, a; and fig. 8, b,
represents
the middle
and last molars of the lower jaw.

"Inhabited a very small island,
covered with thick forest, in the central part of the Chonos
Archipelago."—D.

A mouse obtained on the islets
adjoining the east coast of Chiloe (where Mr. Darwin says it was
common) differs from the above in being a little smaller, the tail is
rather longer, and the ears are a trifle larger. In the feet, claws,
colouring and character of the fur it agrees, and likewise in the pale
colour and slenderness of the incisors. Its dimensions are as follows:—

In.

Lines.

In.

Lines.

Length

from nose to root of tail . .

4

0

Length from nose to ear . . .

0

10½

of tail . . . .
. .

3

0

of ear . . . . .

0

4

of tarsus (claws included) .
.

0

10

I have not the means of satisfying
myself whether this be a distinct species or not; but I think it is
not.

DESCRIPTION.—Fur moderate; ears
moderate; tail shorter than the body; general colour gray washed with
yellow; under parts grayish white. On the upper parts and sides of the
head and body the hairs are gray, broadly annulated with yellow near
the apex, and dusky at the apex; the mixture producing a yellowish
gray tint, approaching somewhat towards olive:—the hairs on the under
parts of the body and throat are deep gray at the base, and white at
the apex; the hairs of the feet are brownish white. The tail is
tolerably well clothed with hairs; those on the upper surface are
brown, and those on the under are dirty white. The ears are well
clothed, both externally and internally, with hairs of the same colour
as those on the upper parts of the body. The hairs of the moustaches
are for the most part whitish, and black at the base. The upper
incisors are pale yellow, and the lower incisors are yellowish white.

In.

Lines.

In.

Lines.

Length

from nose to the root of tail
. .

5

1

Length of tarsus (claws
included) . .

0

11

of tail . . . .
. .

2

8

of ear . . . . .

0

5

from nose to base of ears . .

1

2

Habitat, Valparaiso (August and
September,) Coquimbo (May.)

Subsequent to the description of this
species, under the name of M.
olivaceus in the Zoological Society's
Proceedings, I have imagined that perhaps that name might mislead as
regards the colouring of the animal;—it certainly has a slight olive
hue, but it is not very evident. I have therefore changed the name, and
substituted that of the author of the "Naturgeschichte der Säugethiere
von Paraguay," &c.

In the collection there are three
specimens of the present species; in one of these the hairs of the
upper part and sides of the body are annulated with yellowish white,
instead of yellow; hence the general hue of these parts is nearly gray.

Mus Renggeri is larger than
Mus
Musculus, and much stouter in its proportions; the fur is
shorter,
much less dense, and less soft than in Mus brachiotis.

"It inhabits dry stony places, where
only a few thickets grow."—D.

15. MUS OBSCURUS.

PLATE XV.—Fig. 2.

Mus obscurus, Waterh.,
Proceedings of
the Zoological Society of London for February 1837, p. 16.

DESCRIPTION.—Head large; ears moderate;
tail shorter than the body; fur rather long and glossy; the general
hue of that of the upper parts and sides of the head and body is
blackish brown, and that of the under parts is dirty yellowish white.
The hairs on the upper parts are of a deep lead colour at the base,
black at the apex, and narrowly annulated with dark yellow near the
apex; those of the throat and belly are lead colour at the base and
yellowish at the tip; the chin is white: around the eye, and on the
lower part of the cheeks a deep yellow tint prevails. The ears are well
clothed with hairs both externally and internally, and these are for
the most part of a deep brown colour, as are also the hairs which cover
the feet. The tail is well clothed with hairs, those on the upper
surface are black, and those on the under are dirty white. Both upper
and lower incisors are yellow, but the lower are paler than the upper.

In.

Lines.

In.

Lines.

Length

from nose to root of tail . .

5

3

Length of tarsus (claws
included) . .

0

11½

of tail . . . .
. .

2

7

of ear . . . . .

0

4

from nose to ears . .

1

2½

Habitat, Maldonado, La Plata, (June.)

The present species, like the foregoing, is much stouter
than the
common

DESCRIPTION.—Fur moderately long and
loose; ears rather small; tail shorter than the body; general colour
gray washed with yellow, the yellow colour prevailing, especially on
the sides of the body; muzzle, inner side of ears, and tarsus, of a
rich yellow colour; toes, chin, throat, under parts of body, and rump,
white; all the fur deep gray at the base; the hairs on the upper
parts and sides of the body broadly annulated near the apex with rich
yellow, and at the apex dusky; on the under parts of the body the
hairs are broadly tipped with white. Tail rather sparingly furnished
with hair, that on the upper surface brown, on the sides yellow, and on
the under surface whitish. The hairs of the moustaches are white—some
of them dusky at the base. The incisor teeth are rather slender, and of
a pale yellow colour.

In.

Lines.

In.

Lines.

Length

from nose to root of tail . .

3

6

Length of tarsus (claws
included) . .

0

9

of tail . . . .
. .

1

7½

of ear . . . . .

0

3¾

from nose to ear . .

0

10

Habitat, Hardy Peninsula, Tierra del
Fuego, (February.)

The white, which is usually confined to
the under parts of the body, in this

DESCRIPTION.—Fur moderately long and
loose; ears small; tail nearly equal to the body in length: general
colour gray, with a wash of very pale yellow; chin, throat, and under
parts of the body, white. Tail tolerably well clothed with hairs, those
on the upper surface brown, and those on the under, whitish; on the
sides are some yellowish hairs. Ears with yellow hairs on the inner
side; tarsi pale yellow, toes white; muzzle and around the eye
yellowish.

In.

Lines.

In.

Lines.

Length

from nose to root of tail . .

3

6*

Length of tarsus (claws
included) . .

0

9½

of tail . . . .
. .

2

1

of ear . . . . .

0

4

from nose to ear . .

1

1

Habitat, Santa Cruz and Port Desire, (December.)

"Very common in long dry
grass in the valleys of Port Desire."—D.

The skull is figured in Plate 33, fig.
5, c. Fig. 5, a. represents the molars of the
upper jaw; fig. 5, b.
those of the under jaw, and fig. 5, d.
represents the posterior molar
of the under jaw when more worn.

It was with some hesitation that I
described this as a distinct species in the Society's Proceedings. I
have now re-examined the specimens, and still am

* The dimensions given in the
Proceedings of the Zoological Society were taken from a younger
specimen than those here described, and there is an error in the length
of the tail there given, which should be 1-10 instead of 2-10.

unable to satisfy myself whether they
are varieties of Mus xanthorhinus
or not. Both of Mus canescens
and of
Mus xanthorhinus, I have
before me what I imagine to be an adult and a
young specimen. The adult and the young of M. xanthorhinus
agree in
being of a yellowish-brown
colour, and in having the muzzle and tarsi
deep yellow; both specimens of Mus
canescens are of a gray
colour,
with an indistinct yellow wash, the muzzle and tarsi being tinted with
yellow, as in M. xanthorhinus.
Besides this difference in tint, which,
perhaps, is unimportant, M. canescens
differs from M. xanthorhinus
in
having the head larger, the tail rather longer, and the fur less soft.
The specimens of this animal are both from Patagonia; one of the
specimens of Mus xanthorhinus
was brought by Mr. Darwin from Terra del
Fuego; and as the other formed part of Captain King's collection, it
in all probability came from the same locality. As I only possess one
skull, I cannot speak with certainty as regards the size of the head;
the difference, however, in the stuffed specimens is considerable, and
it is strange that each of the pairs should agree so perfectly,
supposing the difference to be the work of the stuffer's hands.

18. MUS LONGIPILIS.

PLATE XVI.

Mus longipilis, Waterh.,
Proceedings of the Zoological Society of London for February 1837, p.
16.

DESCRIPTION.—Fur very soft and silky,
and extremely long—the ordinary fur of the back measuring nearly three
quarters of an inch, and the longer hairs one inch in length; ears
moderate; tail nearly as long as the body; muzzle much pointed;
general colour gray, washed with yellow, the under parts pale gray, or
grayish white; feet brown; ears and tail well clothed; the hairs on
the inner side of the ears are chiefly of a yellow colour, those on the
upper surface of the tail are brown black, those on the under part are
dirty white; the hairs of the back are deep gray at the base, broadly
annulated with yellow near the apex, and dusky at the apex; the longer
hairs are grayish black; the hairs of the moustaches are dusky at the
base, and whitish beyond that part; the claws are long, and but
slightly curved; the

DESCRIPTION. — Muzzle very long and
pointed, ears small, tail shorter than the body, claws long and but
slightly arched; inner, rudimentary toe of the fore foot furnished
with a pointed claw; fur moderate, and slightly glossy: general
colour yellowish brown, of the sides of the body yellow, of the under
parts pale yellow; the chin, throat and chest whitish: feet brown;
ears well clothed with hairs, those on the inner side are most of them
yellow, but some are black. All the fur is of a deep lead colour at the
base; the hairs on the upper parts and sides of the head and body are
broadly annulated with deep golden yellow near the apex, and blackish
at the apex; on the upper parts long brownish black hairs are thickly
interspersed with the ordinary fur, but on the side of the body they
are less numerous, hence on this part

the yellow tint prevails; on the under
parts of the body the hairs are broadly tipped with pale yellow, and in
parts with white: the tail is but sparingly clothed with hairs, those
on the upper surface are of a dark brown colour, and those on the under
are pale brown. The incisors are very slender and of a very pale yellow
colour.

In.

Lines.

In.

Lines.

Length

from nose to root of tail . .

5

2

Length of tarsus (claws
included) . .

1

0½

of tail . . . .
. .

2

8

of ear . . . . .

0

5

from nose to ear . .

1

3

Habitat, Maldonado, La Plata, (June.)

The specific name nasutus
has been
applied to this mouse on account of its elongated and slender muzzle*,
the tip of which extends nearly 4 lines beyond the upper pair of
incisors: the rudimentary toe of the fore foot, instead of having the
usual rounded nail, has a short pointed claw. Its fur is not so soft,
nor yet so long as in many of the preceding species, and there is a
greater admixture of yellow in its colouring. The claws appear to be
adapted to burrowing.

The skull (which is not quite perfect)
is figured in Plate 33, fig. 7, a,
its length is 1 in. 3 lines. Fig. 7,
b, represents the molars of
the upper jaw, and fig. 7, c,
those of the
under jaw. The lower jaw, which is of a very slender and elongated
form, is figured in Plate 34, fig. 10, a.

"Was caught in a small thicket on an
open grassy plain, by a trap baited with a piece of bird. This mouse
when alive possesses a marked character in the extreme acumination of
its nose."—D.

20. MUS TUMIDUS.

PLATE XVIII.

Mus tumidus, Waterh.,
Proceedings of
the Zoological Society of London for February 1837, p. 15.

inner toe of the fore foot with a
distinct, pointed claw; claws rather large, those of the fore feet but
slightly arched. Fur rather long, and moderately soft; general tint of
the upper parts of the body, brown, of the sides of the head and body,
grayish, but with a yellow wash; the lower part of the sides of the
body and of the cheeks, the tip of the muzzle, and the whole of the
under parts, white; feet dirty white; ears densely clothed with short
hairs, those on the inner side chiefly of an ashy-brown colour, and
those on the outer side dusky; the hairs of the back are of a deep
lead colour at the base, black at the tip, and annulated with yellow
near the tip; the longer hairs, which are thickly interspersed, are
totally black; on the under parts of the body the hairs are gray at
the base, and broadly tipped with white; the upper surface of the
muzzle is blackish; the moustaches are black; the incisors are yellow.

In.

Lines.

In.

Lines.

Length

from nose to root of tail . .

6

9

Length of tarsus (claws
included) . .

1

6

of tail . . . .
. .

5

4

of ear . . . . .

0

7

from nose to ears . .

1

8

Habitat, Maldonado, La Plata (June.)

This species is about the size of Mus
Rattus, but is stouter in its proportions; as in Mus nasutus,
the
thumb is furnished with a pointed claw. The molars of the lower jaw are
figured in Plate 34, fig. 11, a.

"This rat was caught in so wet a place
amongst the flags bordering a lake, that it must certainly be partly
aquatic in its habits."—D.

DESCRIPTION.—Head somewhat arched, and
rather short; ears small; tail about equal in length to the head and
body, measured in a straight line; tarsi large. Fur long, and rather
soft; general colour deep golden yellow: on the upper surface of the
head and the back, long glossy black hairs are thickly interspersed,
and produce, with the admixture of the deep golden

colour of the ordinary fur, a dark
brown tint; chin, throat, chest, and rump, white; the hairs covering
the upper surface of the feet are of a dirty yellowish-white colour,
and on the toes nearly white: ears densely clothed with longish hairs,
those on the inner side chiefly of a deep golden colour, and those on
the outer side brownish; the ears are partially hidden by the long fur
of the head; tail sparingly clothed with hairs, above brown, and
beneath brownish-white: the fur of the back is of a deep gray colour
at the base, annulated with deep golden yellow near the apex, and
blackish at the apex; the longer hairs are black; the hairs of the
belly are pale gray at the base, and broadly tipped with golden yellow
colour; the white hairs on the throat, chest, and rump are of an
uniform colour—not tinted with gray at the root;—the hairs of the
moustaches are black: the incisors of the upper jaw are of a deep
orange colour, and those of the lower jaw are yellow: the thumb nail
is
truncated.

In.

Lines.

In.

Lines.

Length

from nose to root of tail . .

8

6

Length of tarsus . .

2

0

of tail . . . .
. .

7

9

of ear . . . . .

0

6½

from nose to ear . .

1

8

Habitat, Bahia Blanca, (September.)

This species is nearly equal in size to
the common rat (Mus decumanus).
Of its skull * I possess but the
anterior portion (see Pl. 33. fig. 3, a.
and 3, b.): it appears to
have
been about the same size as that of M.
decumanus, its proportions,
however, are different: the nasal portion is broader and shorter, the
ant-orbital outlet is rather smaller; the plate, forming the anterior
root of the zygomatic arch, and which protects this outlet, has its
anterior edge distinctly emarginated, and not nearly straight as in M.
decumanus,—the zygomatic arch is stouter, the space between the
orbits
is narrower, the palate is more contracted, the incisors are much
broader, less deep from front to back, and have the anterior surface
more convex; the molar teeth are larger; the lower jaw (see Plate 34.
fig. 12, a.) when compared
with that of Mus decumanus also
offers many
points of dissimilarity; the principal differences consist in its
greater strength, the comparatively large size and breadth of the
articular surface of the condyles, the upright position of the coronoid
process—a perpendicular line dropt from the apex of which would touch
the posterior part of the last molar—and the great

* I am sorry to say the artist has not
drawn this skull with his usual fidelity, a circumstance which I did
not perceive until it was too late to make any alteration: it is too
large, and the incisors are represented as projecting forwards too
much; they are in the original so nearly at right angles with the upper
surface of the skull that but a very small portion of them is seen,
when it is viewed, as represented at fig. 3, a.

extent of the symphysis menti.
In the
form of the incisors, the more contracted palate, the great extent of
the symphysis menti, and in
fact in most of the points of
dissimilarity, between the skull of the present animal and that of Mus
decumanus, here pointed out, it will be perceived, there is an
approach made to the Arvicolidæ.

The dimensions of the skull (so far as
an imperfect specimen will allow of their being taken) are as follows:—

In

Lines.

Distance
between front of
incisors,
(upper jaw) and the first molar tooth

0

8

Longitudinal
extent of the three
molars
on either side, taken tggether .

"This rat was caught at Bahia Blanca
where the plains of Patagonia begin to blend into the more fertile
region of the Pampas. It lived in holes amongst the tussocks of rushes,
on the borders of a small, still, brook; in its manner of diving and
aquatic habits it closely resembled the English water-rat, (Arvicola
amphibia.)"—D.

When at Paris I examined what I believe
to be the original Mus Braziliensis,
since the specimen was labelled
"Rat de Brazil St. Hilaire,
1818." It agrees perfectly with the present
animal excepting in being rather smaller, the length from the nose to
the tail being 7 inches and 4 lines—the length of the tail is 7 inches
9 lines, and that of the tarsus is 1 inch 11 lines; this difference in
the length of the body may arise from difference of age, or even of
sex. In the Paris Museum I saw what appeared to me to be a variety of
the same species in which the under parts of the body are white.

It appears from this description that
the Mus Angouya is a smaller
animal, and differs both in colouring and
proportions from the Mus Braziliensis.
Brandt has figured and described
a rat under the name of Mus Angouya,
which in many respects agrees
better with Azara's description; there are, however, discrepancies in
the dimensions.

22. MUS MICROPUS.

PLATE XX.

Mus micropus, Waterh.,
Proceedings of
the Zoological Society of London for February 1837, p. 17.

DESCRIPTION.—Form stout, ears rather
small, tail nearly equal to the body in length, fur very long and
moderately soft, general colour of the upper parts of head and body,
brown; of the sides of the body grayish, faintly washed with yellow,
of the under parts grayish white, faintly tinted with yellow; hair
covering the upper surface of the feet dirty white; on the tarsus
there is a very slight yellow tint; ears well clothed with hairs,
those on the inner side chiefly of a yellow colour; tail above, dusky
brown; beneath dirty white: hairs of moustaches black at the base and
grayish at the apex; incisors pale yellow: hairs of the back deep
gray at the base, annulated with brownish yellow near the apex, and
dusky at the apex; longer hairs dusky black; hairs of the belly deep
gray at the base and broadly tipped with yellowish white.

DESCRIPTION.—Ears large; tail rather
shorter than the head and body taken together; tarsi slender, and
moderately long; fur long and very soft; general tint of the upper
parts of head and body grayish, washed with brownish yellow; on the
sides of the body a palish yellow tint prevails; feet, chin, throat,
and under parts of body pure white; tail rather sparingly clothed with
hairs, those on the apical portion rather long, and forming a slight
pencil at the tip; on the upper side and at the tip of the tail the
hairs are brown, on the under side they are dirty white; the ears are
very sparingly clothed with minute brownish yellow hairs internally;
externally, on the fore part, the hairs are rather longer and of a
brown colour; the upper incisors are orange, and the lower incisors
are yellow; the hairs of the moustaches are long, and of a black
colour; the hairs of the back are deep gray at the base, brownish at
the tip, and annulated with pale brownish yellow near the tip; the
longer hairs are brown; the hairs of the belly are white externally,
and gray at the base; on the throat the hairs are white to the root.

In.

Lines.

In.

Lines.

Length

from nose to root of tail . .

6

8

Length of tarsus (claws
included) . .

1

2½

of tail . . . .
. .

5

6

of ear . . . . .

0

8

from nose to ear . .

1

4½

Habitat, Northern Patagonia (August.)

The molars of the upper jaw are figured
in Plate 34, fig. 15, a, and
those of the lower jaw, fig. 15, b.

DESCRIPTION. — Ears rather large, tail
rather longer than the body, tarsi moderately long and somewhat
slender: fur long and very soft: prevailing tint pale yellow; on the
back
there is a brownish hue owing to the long hairs, which are thickly
interspersed with ordinary fur, being of that colour: in the region of
the tail the hairs are of a rich yellow colour; the tip of the muzzle
is white, the feet, chin, throat and the whole under parts of the body
are white; on the chest and belly a faint yellowish hue is observable:
the tail is well clothed with tolerably long hairs, those on the
apical portion are the longer, on the upper side of the tail they are
of a brown colour, and on the under side they are pure white: the ears
are well clothed with tolerably long hairs, those on the inner side are
of a pale yellowish colour, externally on the fore part they are brown,
and on the hinder part they are yellowish white: the hairs of the
moustaches are numerous and very long; some of them are white, but the
greater portion are brownish black at the base and whitish at the apex:
the upper incisors are yellow, and the lower are yellow-white: the
hairs of the ordinary fur on the back are gray at the base, brownish at
the tip, and very pale yellow near the tip: the hairs on the belly are
gray at the base and white externally.

In.

Lines.

In.

Lines.

Length

from nose to root of tail . .

5

3

Length of tarsus (claws
included) . .

1

1

of tail . . . .
. .

3

10

of ear . . . . .

0

7

from nose to ear . .

1

3

There are three specimens of the
present species in Mr. Darwin's collection; two of them were caught
when shedding their fur, and having lost the longer black hairs, have
the upper parts of the body of a paler colour; their general tint is
very pale, and may be described as gray, with a wash of pale yellow.

This species is closely allied to the
last, but differs in being rather smaller, in having smaller ears which
are well clothed with hair, and not sparingly furnished as in Mus
griseo-flavus, and in having a shorter tail which, like the
ears, is
more densely clothed with hairs; in the structure of the molar teeth
there also differences which will be better understood by comparing the
drawings. Fig. 16, a, Plate
34, represents the molars of the upper jaw,
and 16, b, those of the lower
jaw.

"Extremely abundant in the coarse
grass and thickets in the ravines at Port Desire and Santa Cruz: was
caught in a trap baited with cheese."—D.

25. MUS DARWINII.

PLATE XXIII.

Mus Darwinii, Waterh.,
Proceedings of
the Zoological Society of London for February 1837, p. 28.

DESCRIPTION.—Form robust; ears
immensely large; tail nearly equal in length to the head and body
taken together; fore feet very small; tarsi moderate; fur very long
and soft; general tint of the upper parts pale cinnamon yellow; on
the rump a richer yellow hue prevails, and on the back there is a
brownish tint, owing to the interspersed long hairs being of that
colour; the upper surface of the head is grayish; the cheeks, like
the sides of the body, are of a delicate yellow colour, faintly clouded
with brown; the sides of the muzzle, lower part of the cheeks and
sides of the body, and the whole under parts, are pure white; the feet
and tail are also white, if we except the upper surface of the latter,
which is dark brown; the yellow tint of the sides of the body is
extended downwards on the outer side of the fore legs and on the back
of the hinder legs; the ears are but sparingly furnished with hair,
excepting on the fore part, externally, where they are of a brownish
colour; the minute hairs which cover the remaining parts of the ear
are very pale; the tail is well clothed with hairs; the hairs of the
moustaches are numerous and very long; they are for the most part
blackish at the base, and gray at the apex; the incisors are rather
slender, the upper pair are an orange colour, and the lower, yellow;
the hairs of the ordinary fur of the back are gray at

the base, broadly annulated with pale
cinnamon yellow near the apex, and brownish at the apex; the hairs of
the belly are deep-gray at the base, and white externally, those on the
throat are pale gray at the base.

In.

Lines.

In.

Lines.

Length

from nose to root of tail . .

6

0

Length of tarsus (claws
included) . .

1

1½

of tail . . . .
. .

4

9

of ear . . . . .

0

11¾

from nose to ear . .

1

4½

Width of ear . . . . .

1

0½*

Habitat, Coquimbo, Chile, (May.)

This species is evidently allied to the
two preceding; and perhaps the "Rat quatrieme, ou Rat oreillard" of
Azara, (Mus auritus, Desm.)
will form one of this little group. The
molar teeth of the upper jaw are figured in Plate 34, fig. 17, a—
those
of the lower jaw, fig. 17, b.

DESCRIPTION.—Ears moderate, slightly
pointed; tarsi moderate; tail slender, nearly as long as the head and
body; fur long, and not very soft; upper parts of the body of a
brownish hue, a tint produced by the admixture of black and palish
yellow hairs; on the sides of the body the longer black hairs are less
abundant, and the prevailing colour is yellow; under parts of the body
white, with a very faint yellow tint; feet furnished above with dirty
white hairs; ears rather sparingly clothed with hairs, those on the
inner side of a yellow colour, and those on the outer side dusky; tail
above brown, and beneath whitish; the hairs of the moustaches black;
the incisors deep yellow; the hairs on the back are deep gray at the
base, broadly annulated with palish yellow near the apex, and blackish
at the apex; the longer hairs black; on the belly the hairs are gray
at the base, and broadly tipped with yellowish white.

* It is not easy to measure the width
of the ears in these animals: upon measuring with a thread over
the
curve of the outer side I have found the width of the ears of the
present animal to be as above given,—the dimension slightly exceeding
that stated in the Proceedings of the Zool. Soc.

This species is less than Mus
Rattus.
The upper parts of the body have a slightly variegated appearance.

The skull of Mus Galapagoensis
(Plate
33, fig. 8, a,) is rather
smaller than that of M. Rattus,
the nasal
portion is proportionately longer, the cranial shorter, and the
interparietal bone is smaller, especially in antero-posterior extent;
its length is 15 lines, and its breadth is 8 1/8
lines. The lower jaw
is
figured in Plate 34, fig. 14, a.
Fig. 8, b, of Plate 33,
represents the
molars of the upper jaw, and fig. 8, c,
those of the lower jaw.

"This mouse or rat is abundant in
Chatham Island, one of the Galapagos Archipelago. I could not find it
on any other island of the group. It frequents the bushes, which
sparingly cover the rugged streams of basaltic lava, near the coast,
where there is no fresh water, and where the land is extremely
sterile."—D.

DESCRIPTION.—Form stout; ears moderate;
tail equal to the body in length; tarsi moderate; fur very long.
General tint of the upper part and sides of the head and body blackish
brown with an admixture of gray; of the under parts grayish white;
feet brown, the hairs grayish at the tip: tail black and but sparingly
clothed with short bristly hairs: ears rather sparingly clothed with
hairs, which are for the most part of a brownish gray colour. The
ordinary fur of the back is about ¾ of an inch in length and very
soft—of a deep gray colour, broadly annulated with brownish yellow near
the tip and blackish at the tip: the longer hairs which are black,
measure upwards of 1¼ inches in length. The upper incisors are of an
orange colour and the lower are black.

Mammalia not belonging to the order
Marsupiata are rare in the
Continent of Australia. Besides the Dog, we
are acquainted with none excepting a few species of Rodents, and these
all belong to the family Muridæ.

The present animal adds one to the
limited number already known: in the Museum of the Zoological Society
there is another species, the characters of which I will point out in
the next description.

Mus fuscipes is remarkable
for the great
length and softness of its fur, and the brown colour of its feet: it
is rather less than Mus Rattus,
and of a stouter form. Not having had
an opportunity of examining the molar teeth and the cranium of this
animal, I cannot be positive that it is a species of the genus Mus;
in
external characters and the form of the incisor teeth, however, it
agrees perfectly with the animals of that genus.

"This animal was caught in a trap
baited with cheese, amongst the bushes at King George's Sound."—D.

DESCRIPTION.—Ears rather large and
slightly pointed, tarsi slender and tolerably long; tail about equal
in length to the body and half the head; fur long and soft; general
colour pale ochreous yellow; on the back there are numerous long black
hairs interspersed with the ordinary fur, which gives a darker hue and
somewhat variegated appearance to that part; feet, chin, throat, and
the whole under-parts of the body white; ears brown, sparingly clothed
with minute yellow hairs, both externally (excepting on the forepart,
where they are brownish) and internally; tail brownish above, and
yellowish white beneath; the hairs of the moustaches long, and of a
brown colour; upper incisors deep orange, lower incisors yellow;
claws white. The hair of the back is of a deep lead colour at the base,
pale ochre near the apex, and dusky at the apex; the longer hairs are
black; the hairs of the belly are deep gray at the base and broadly
tipped with white.

In.

Lines.

In.

Lines.

Length

from nose to root of tail . .

4

8

Length of tarsus (claws
included) . .

1

0½

of tail . . . .
. .

3

6

of ear . . . . .

0

7

from nose to ear . .

1

0½

VAR. β.—General
colour of the fur pale
ochreous yellow, the feet, under side of the tail and the whole of the
under parts, as well as the lower portion of the

sides of the body, white; hairs of the
back palish gray at the base, those of the belly indistinctly tinted
with very pale gray at the roots; ears and moustaches pale brown.

Habitat, New South Wales.

This species is about half-way between
Mus Rattus and Mus musculus in size, and is
remarkable for its delicate
colouring. The molar teeth are figured in Plate 34; fig. 18. a,
represents the molars of the upper jaw, and fig. 18. b, those
of the
lower.

The present genus according to my views
belongs to the family Muridæ.
The modifications of structure which have
led me to separate it from the genus Mus
are as follows:

External characters. — The
most
conspicuous points of distinction between the external characters of
Reithrodon and Mus (if we regard M. rattus,
M. decumanus or M.
musculus as typical examples of that genus,) consist in the
arched form
of the head, the large size of the eyes, the stout form of the body,
and the upper incisors being grooved. The ears, tail and feet are more
densely

clothed with hairs, and the tarsus is
covered with hair beneath,—at least the hinder portion.

Cranium.—The skulls of the
species of
the present genus differ from those of the species of Mus in
being
proportionately shorter and broader, and more arched; the facial
portion of the skull is larger, compared with the cranial, the space
between the orbits is narrower, and the orbits are larger; the palate
is narrower and the incisive foramina are more elongated and larger.
The pterygoids approximate anteriorly, so that the posterior nares
are
greatly contracted. As in the genus Mus
the anterior root of the
zygomatic arch is directed upwards from the plane of the palate, and
forwards in the form of a thin plate, protecting an opening behind,
which leads into the nasal cavity, and also forming the outer boundary
both of the ant-orbital foramen, and a second opening whose outlet is
directed upwards. This thin plate, however, is narrower than is usually
found in the genus Mus. The
most striking differences observable in the
lower jaw consist in the smaller size of the coronoid process, and its
being curved outwards; the condyloid process is narrower, and the
angle of the jaw, or descending ramus, approaches more nearly to a
quadrate form—the posterior edge of the jaw is more deeply emarginated.

Dentition.—The incisors are
narrow and
compressed as in the genus Mus,
but they are less deep from front to
back; those of the upper jaw (Plate 33. fig 2. b.) have
each
a distinct
longitudinal groove, which is situated nearer to the outer than to the
inner edge of the tooth. Close to the inner edge of each of these teeth
an indistinct second longitudinal groove may be seen by means of a
lens. The lower incisors are nearly equal in width to the upper.

The crowns of the molar teeth in the
young Reithrodon are higher
than in Mus, and they are
rootless; in the
adult animal, however, they possess distinct roots. The folds of enamel
form sigmoid flexures, are closely approximated to each other, and
those of the opposite sides of the tooth meet.

1. REITHRODON CUNICULOÏDES.

PLATE XXVI

Reithrodon cuniculoïdes,
Waterh., Proceedings of the
Zoological Society of London for February
1837, p. 30.

as the body; tarsi rather long; fur
long and very soft. General tint of the upper parts of the body grayish
brown, with a considerable admixture of yellow; of the sides of the
body grayish tinted with yellow; the lower portion of the cheeks, and
the lower half of the sides of the body are of a delicate yellow
colour; the under parts of the head and body are yellowish white; the
fore
part of the thighs is whitish; the rump, feet, and tail are white,
excepting the upper surface of the latter, which is brown; behind each
ear there is a patch of yellowish white hairs. The ears are tolerably
well-clothed with hairs; those on the inner side are for the most part
of a yellow colour, but towards the posterior margin they are brown;
externally, the hairs are also yellow, excepting on the fore part,
where they are dusky brown. The hairs of the moustaches are very long
and numerous; black at the base, and grayish at the apex. The feet are
well clothed with hairs which cover and nearly hide the claws; the
under side of the tarsus is clothed with grayish brown hairs. The tail
is well clothed with tolerably long hairs which completely hide the
scales. The hairs on the back are of a deep gray colour at the base,
broadly annulated with yellow near the apex, and dusky at the apex:
the longer hairs are black: on the throat and belly the hairs are deep
gray at the base, and broadly tipped with pale yellow—towards the
cheeks and sides of the body with a deeper yellow. The incisors are
yellow.

In.

Lines.

In.

Lines.

Length

from nose to root of tail . .

6

5

Length of tarsus (claws
included) . .

1

4¼

of tail . . . .
. .

3

3½

of ear . . . . .

0

7

from nose to ear . .

1

4

Habitat, Patagonia, (April
and
January).

In the arched form of the head this
little animal bears considerable resemblance to a young rabbit, a
resemblance which has struck almost all who have seen it, I have
therefore applied to it the specific name Cuniculoïdes.
The
skull is
figured in Plate 33, fig. 2. a.,
its dimensions are as follows:—

In.

Lines.

Total
length . . . . . . . . . .
. . .

1

4

Width
. . . . . . . . . . . . .
.

0

10

Length
of nasal bones . . . . .
. . . . . .

0

7

of incisive foramina
. . . . . . . . . .

0

4¾

Distance
between the outer
surface of
the incisors and the front molar upper jaw .

0

5

Longitudinal
extent of the three
molars
of the upper jaw . . .
. .

0

3¾

Length
of a ramus of the lower
jaw,
without the incisor . . . . .

0

9¾

The molar teeth of the upper jaw are
figured in Plate 33, fig. 2, c.
and

2, e; of the lower jaw,
fig. 2, d. Fig.
2, b, represents the incisors
of the upper jaw magnified. Fig. 21,
a, Plate 34, represents the
skull, viewed from beneath, fig. 21, b,
is
the side view of the same, and fig. 21, c, is the lower jaw.

"Specimens were procured at Port
Desire, St. Julian, and Santa Cruz; at this latter place they were
caught in numbers, (in traps baited with cheese,) both near the coast
and on the interior plains. A specimen from Santa Cruz weighed 1336
grains. In the early part of January, there were young individuals at
Port St. Julian."—D.

2. REITHRODON TYPICUS.

Reithrodon typicus, Waterh.,
Proceedings of the Zoological Society of London for February 1837, p.
30.

DESCRIPTION.—Ears large; tarsi
moderate; fur moderately long; general tint of the upper parts
brown—of the upper surface of the head blackish; on the cheeks and
flanks a rich yellow tint prevails; the under parts of the head and
body are bright yellow; the feet are white; the tail is brownish
above and dirty white beneath. The ears are tolerably well clothed with
hairs, and these are of a yellowish colour, excepting on the fore part,
externally, where they are brown; the tarsi are covered beneath with
grayish brown hairs; the hairs of the moustaches are numerous and
moderately long, black at the base and grayish at the apex. The hairs
of the back are deep gray at the base, broadly annulated with yellow
near the apex, and black at the apex; on the upper surface of the head
the hairs are very narrowly annulated with yellow, hence a blackish hue
prevails. The longer hairs on the back are black; the hairs of the
throat and belly are gray at the base, and broadly tipped with yellow.
The incisors are yellow.

This species is of a darker colour than
the last, its ears are much larger and the tarsi are shorter. It has
the same rabbit-like appearance. The molar teeth of the lower jaw are
figured in Plate 33, fig. 4, a.

"This mouse, when alive, from its very
large eyes and ears, had a singular appearance, somewhat resembling
that of a little rabbit. It frequents small thickets in the open grassy
savannahs near Maldonado, and was caught with facility by means of
traps baited with cheese. '—D.

DESCRIPTION.—Ears small; tail shorter
than the body; tarsus moderate; fur long and extremely soft. General
hue of the upper parts of the head and body ashy-brown; the lower part
of the cheeks and sides of the body are of a delicate yellow colour;
the under parts of the head and body and the rump are cream colour. The
ears are blackish; * the tail is tolerably well clothed with longish
hairs, which are, however, not so thickly set as to hide the scales—on
the upper side they are blackish brown; on the sides and beneath they
are white. The feet are white. All the fur is of a deep gray colour at
the base; the hairs of the back are of a very pale yellow colour
(almost white) near the tip, and brown at the tip; the longer hairs
are
black at the apex. The incisors are yellow; the hairs of the
moustaches are numerous and very long—some of them are whitish, and
others are black at the root, and gray at the apex.

In.

Lines.

In.

Lines.

Length

from nose to root of tail . .

5

0

Length of tarsus (claws
included) . .

1

0

of tail . . . .
. .

2

4

of ear . . . . .

0

5½

from nose to ear . .

1

2

Habitat, South shore of the Strait of
Magellan, near the Eastern entrance.

This little animal was preserved
in spirit, and has since been mounted, it is

probable, therefore, that the colours
have been slightly changed. It is of a smaller size than either of the
preceding species. Its fur is long, extremely soft, and somewhat
resembles that of the Chinchilla. The ears are smaller, and the tail is
shorter, and less densely clothed with hairs than in Reithrodon
cuniculoides. The skull (see Plate 43, fig. 20, a, 20, b,
and 20, c,)
differs in many respects from that of the species last mentioned. It is
of a smaller size, the nasal portion is proportionately shorter and
narrower, the incisive foramina are shorter; the pterygoid processes
do not approximate so nearly at their base, and the pterygoid fossæ
are very shallow, whereas in R.
cuniculoides they are deep. In the
skull of the animal just mentioned there are two distinct longitudinal
grooves on the palate, which extend backwards from the incisive
foramina, and terminate in two rather large and deep excavations:
these excavations are in the palatine bone, and situated between the
last molar teeth; they are separated from each other by a narrow,
longitudinal, elevated ridge; a narrow ridge also separates them from
the pterygoid fossæ. At the bottom of each of these hollows are
several minute foramina, and in front of them there are two larger
longitudinal foramina. In R.
chinchilloides, the longitudinal grooves
on the palate and the posterior hollows are shallow, and consequently
much less distinct; the pterygoid fossæ are very nearly on the same
plane as the palate, and are indicated only by a very slight
depression. The incisor teeth are broader than in R. chinchilloides,
and the molar teeth are proportionately smaller. The thin plate which
forms the anterior root of the zygomatic arch is deeply emarginated in
front in R. cuniculoides (see
Plate 34, fig. 21, b.); but
in R.
chinchilloides, the anterior margin of this plate is nearly
straight,
(see Plate 34, fig. 20, c.)

In the form of the lower jaw of the two
animals under consideration there are differences which will be more
clearly understood upon comparing the figures. I will therefore merely
notice one remarkable character which is found in R. cuniculoides,
and
that is, that the condyloid process is rather deeply concave on the
inner side, a character which does not exist in R. chinchilloides,
nor
do I recollect having observed it in any other Rodent.

The principal dimensions of the skull
of R. chinchilloides, are as
follows: —

In.

Lines.

Total
length . . . . . . . . . .
. . .

1

2

Width
. . . . . . . . . . . . .
.

0

8½

Length
of nasal bones . . . . .
. . . . . .

0

6 1/3

of incisive foramina
. . . . . . . . . .

0

4

Distance
between the outer
surface of
the incisors and the first molar tooth, upper jaw .

0

4½

Longitudinal
extent of the three
molars
of the upper jaw, taken together . . .

In the foregoing descriptions I have
endeavoured to convey an idea of the characters of the species of mice
submitted to me for examination and description, by Mr. Darwin: there
are, however, some points upon which I have been silent in my
descriptions. I allude to the characters observable in the dentition. I
have omitted to notice the various modifications in the structure of
the molar teeth, because I found it would lengthen the descriptions to
no good purpose, inasmuch as of almost all the species I have made
outlines of the molars, which will convey a more clear idea than any
verbal description can do.

Upon an inspection of the Plates, it
will be seen, that by far the greater portion of the teeth figured, may
be referred to one particular type of form or pattern, and that this
pattern does not agree with that observed in the molars of Mus
Rattus,
M. decumanus, or M. musculus, whilst these three
species agree
essentially with each other.

In the young Black Rat (Mus Rattus),
before the teeth are worn, the two anterior molar teeth, on either side
of the upper jaw, present three longitudinal rows of tubercles, a
central series of larger tubercles, and on each side of these, a row of
smaller ones. The front molar has three of the larger tubercles
arranged along the middle of the tooth; three smaller ones on the
outer side, and two, on the inner side. The second molars have two
central tubercles, two outer, and two inner ones. The posterior molar
is nearly round, the body of the tooth consists of three principal
tubercles, and one small tubercle, situated on the inner and anterior
portion of the tooth.

The corresponding teeth in the young of
Mus bimaculatus present a very
different appearance; the molars,
instead of having three longitudinal rows of tubercles, have only two.
An idea of the appearance of these teeth may be formed by removing the
inner row of tubercles from the molars of Mus rattus. We
should then
have, as in Mus bimaculatus,
molars of a narrower form, the first tooth
presenting six tubercles, the second, four; and the posterior tooth
devoid of the small inner lobe; the opposing tubercles of each tooth,
however, in M. bimiculatus,
are of equal size.

The molars of the lower jaw of Mus
bimaculatus agree with those of M. Rattus as to the
number of
tubercles
which they possess; they are, however, proportionately longer and
narrower, and, when a little worn, these teeth, as well as those of the
upper jaw, differ considerably from those of M. Rattus. In
the last
named animal, when the molars are slightly worn, the ridges of enamel
run completely across the tooth, as in Figs. 18 and 19, Plate 34. Such
is not the case

in M. bimaculatus at any
age. As soon
as the molar teeth are worn, the folds of enamel penetrate the body of
the tooth on each side, and those of one side alternate with those of
the other,—in fact, they very nearly resemble those of the Hamsters
(Cricetus).

I have selected the molar teeth of Mus
Rattus and M. bimaculatus
for comparison, since I happened to possess
specimens displaying both the young and adult states of each. But had I
selected, on the one hand, almost any of the species brought from South
America by Mr. Darwin, and, on the other hand, the Mus musculus
or M.
decumanus, I should have had to point out the same
distinctions—the
former agreeing in dentition with M.
bimaculatus, and the latter with
M. Rattus.

The differences pointed out, between
the molar teeth of Mus Rattus
and those of M. bimaculatus,
I cannot but
consider as important, since all the Old World species of Mus
which I
have yet had an opportunity of examining (and they are numerous) agree
essentially with the former, whilst the only Mus from S.
America
(excepting M. Musculus and M. decumanus, which are
carried in
ships to
all parts of the world) in which I have as yet found molar teeth like
those of M. Rattus, is the Mus Maurus, and this it
has been
stated is
possibly a variety of M. decumanus.

Although as yet I have not met with
species in the Old World possessing the characters of the South
American Muridæ, among those
of North America, several have come under
my observation. The Mus leucopus,
Symidon hispidum, and the
species of
Neotoma certainly belong to
the same group,* as does also the species
of the Galapago Islands, described in this work under the name
Galapagoensis.

These considerations have induced me to
separate the South American mice from those of the Old World,—or rather
from that group of which M. decumanus
may be regarded as the type,—and
to place them, together with such North American species as agree with
them in dentition, in a new genus bearing the name Hesperomys.†

Whether this group be confined to the
Western hemisphere or not, I will not venture to say, but I
think I may safely affirm that that portion of the globe is their chief
metropolis.

The species of the genus Hesperomys,
which depart most from the type—whose dentition is least like figs. 5,
a, and 5, b, Plate 33. or 6, a, and 6, b,
of the

* I am acquainted with seven North
American Species of Muridæ,
all of which possess the dentition of
Hesperomys.

same Plate—recede still farther from
the genus Mus, and approach
more nearly (as regards the dentition) to
the Arvicolidæ. Among the
species here described I may mention as
examples, M. griseo-flavus, M. zanthopygus, and M.
Darwinii;—see the
molar teeth figured in Plate 34. figs. 15, 16, and 17, —and among the
North American species, those constituting the genus Neotoma.
The
latter make by far the nearest approach to the Arvicolidæ of any which
have yet come under my observation, not only in the dentition, but in
the form of the skull and the large size of the coronoid process of the
lower jaw; there is, nevertheless, a tolerably well marked line of
distinction between the crania of the Arvicolidæ
and Neotoma.

The skulls of the animals belonging to
the genera Castor, Ondatra, Arvicola, Spalax,
and Geomys, which
constitute the principal groups of the family Arvicolidæ,
when compared
with those of the family Muridæ,
present, among others, the following
distinctive characters.

The temporal fossæ are
always much
contracted posteriorly, by the great anterior and lateral development
of the temporal bones; the plane of the inter-molar portion of the
palate is below the level of the anterior portion; the coronoid
process of the lower jaw is very large, the articular portion of the
condyloid process is proportionately broad; the descending ramus, or
posterior coronoid process, is so situated that its upper portion
terminates considerably above the level of the crowns of the molars;
this same process is generally * directed outwards from the plane of
the horizontal ramus. The incisor teeth of the Arvicolidæ
differ from
those of the Muridæ in being
proportionately broader and less deep from
front to back—they are not laterally compressed as in Mus.
The molar
teeth are rootless,† and the folds of enamel are the same throughout
the whole length of the tooth; whereas in Mus they enter
less and less
deeply into the body of the tooth as we recede from the crown, and
towards the base of the visible portion (the tooth being in its
socket)
the indentations of the enamel are obliterated.

Now in the species of Hesperomys,
the
molar teeth are always rooted, and in the form of the skull and the
lower jaw they agree with the Muridæ,
and do not

* I am acquainted with only one
exception, and that is in the genus Castor.
In the genus Ondatra, the
descending ramus is but slightly twisted outwards, but in all the other
Arvicolidæ, whose crania I
have examined, it is remarkably so, and in
the genera Spalax and Geomys, where this character
is
carried to the
extreme, the descending ramus projects from the alveolus of the long
inferior incisors, in the form of a rounded and almost horizontal plate.

† In aged individuals of some of
the species of Arvicolidæ,
the molar teeth possess short roots. In a
skull of Ondatra now before
me I find all the molars divided at the
base into two portions, which in all probability would have formed
solid roots had the animal lived longer.

present the characters above pointed
out as distinguishing the Arvicolidæ,
and as regards the cranium and
lower jaw, it is only in the genus Neotoma
that any approach is evinced.

Of the various groups of the order
Rodentia found in South
America, the Sciuridæ, so far
as I am aware,
are chiefly confined to the more northern parts, and do not occur in
the most southern; the Myoxidæ,
Gerboidæ, and Arvicolidæ are wanting.
The species of the family Muridæ
belong to different sections to those
of the Old World. Of the Leporidæ
I am acquainted only with one well
established species—the Lepus
Braziliensis, which however is not found
"in tota America Australi," as Fischer says, there being no Hare yet
found in the more southern parts, where the Cavies and Chinchillas
appear to take their place. The remaining South American
Rodents—certain species of Hystricidæ,
the genera, Echimys, Dasyprocta,
Cælogenys and Myopotamus, together with the Octodontidæ
and
Chinchillidæ, all possess a
peculiar form of skull and of the lower
jaw, (more or less approaching to figs. 1, Plate 33, and figs. 23,
Plate 34.) which I have described in the "Magazine of Natural
History," for February 1839, and which is rarely found in the North
American, or Old World Rodents. In enumerating the above groups, I
omitted the Caviidæ, because
in the form of the lower jaw they differ
somewhat from the rest—they possess, in fact, a form of lower-jaw
peculiar to themselves; but in the Chinchillas * the transitions
between
one form and the other are found.

The South American Muridæ,
which form
the chief part of Mr. Darwin's collection, were none of them procured
further north than latitude 30°, with the exception of those from the
Galapagos Archipelago. The species occur at the following localities.

WEST
COAST OF SOUTH AMERICA.

EAST
COAST OF SOUTH AMERICA.

MALDONADO.

GALAPAGOS
ARCHIPELAGO.

Mus decumanus.

— maurus.

Mus
Jacobiæ.

— Musculus.

—
Galapagoensis.

— tumidus.

— nasutus.

Coquimbo.

— obscurus.

— arenicola.

Mus
longipilis.

— bimaculatus.

—
Renggeri.

— flavescens.

— Darwinii.

— Reithrodon
typicus.

* See Proceedings of the Zoological
Society for April 9th, 1839, p. 61.

"This animal, in Chile, is known by
the name of "Coypu;" at Buenos Ayres, where an extensive trade is
carried on with their skins, they are improperly called 'nutrias,' or
otters. In Paraguay, according to Azara, their Indian name is 'guiya.'
On the east side of the continent they range from Lat. 24° (Azara)

to the Rio Chupat in 43° 20';—distance
of 1160 miles. This latter river is 170 miles south of the Rio Negro,
and the intervening space consists of level, extremely arid, and almost
desert plains, with no water, or at most one or two small wells. As the
Coypu is supposed never to leave the banks of the rivers, and being,
from its web-feet and general form of body, badly adapted for
travelling on land, its occurrence in this river is a case, like so
many others in the geographical distribution of animals, of very
difficult explanation. The same remark is indeed applicable, but with
less force, to its existence in the Rio Negro. On the west coast, it is
found from the valleys of central Chile (Lat. 33°) to 48° S., or
perhaps even somewhat farther, but not in Tierra del Fuego. So that, on
the Atlantic side of the continent, the plains of Patagonia check its
range southward, as, on the Pacific side, the deserts of Chile do to
the north. Its range, including both sides, is from 24° to 48°, or 1440
miles. In the Chonos Archipelago these animals, instead of inhabiting
fresh water, live exclusively in the bays and channels which extend
between the innumerable small islets of that group. They make their
burrows within the forest, a little way above the rocky beaches. I
believe it is far from being a common occurrence, that the same species
of any animal should haunt indifferently fresh water, and that of the
open sea. We shall see that the Capybara is sometimes found on the
islands near the mouth of the Plata; but these cannot be considered as
their habitual station in the same manner as the channels in the Chonos
Archipelago are to the Coypu. The inhabitants of Chiloe, who sometimes
visit this Archipelago for the purpose of fishing, state that these
animals do not live solely on vegetable matter, as is the case with
those inhabiting rivers, but that they sometimes eat shell-fish. The
Coypu is said to be a bold animal, and to fight fiercely with the dogs
employed in chasing it. Its flesh when cooked is white and good to eat.
An old female procured (January) amongst these islands, weighed between
ten and eleven pounds." D.

together my observations on the less
known animals. The Tucutuco is exceedingly abundant in the
neighbourhood of Maldonado, but it is difficult to be procured, and
still more difficult to be seen, when at liberty. Azara,* who has given
an account of its habits, with which every thing I saw perfectly
agrees, states that he never was able to catch more than one, although
they are so extremely common. The Tucutuco lives almost entirely under
ground, and prefers a sandy soil with a gentle inclination; but it
sometimes frequents damp places, even on the borders of lakes. The
burrows are said not to be deep, but of great length. They are seldom
open; the earth being thrown up at the mouth into hillocks not quite
so large as those made by the mole. Considerable tracts of country are
completely undermined by these animals. They appear, to a certain
degree, to be gregarious; for the man who procured my specimens had
caught six together, and he said this was a common occurrence. They are
nocturnal in their habits; and their principal food is afforded by the
roots of plants, which is the object of their extensive and superficial
burrows. In the stomach of one which I opened I could only distinguish,
amidst a yellowish green soft mass, a few vegetable fibres. Azara
states that they lay up magazines of food within their burrows.

"The Tucutuco is universally known by
a very peculiar noise, which it makes when beneath the ground. A
person, the first time he hears it, is much surprised; for it is not
easy to tell whence it comes, nor is it possible to guess what kind of
creature utters it. The noise consists in a short, but not rough, nasal
grunt, which is repeated about four times in quick succession; the
first grunt is not so loud, but a little longer, and more distinct than
the three following: the musical time of the whole is constant, as
often as it is uttered. The name Tucutuco is given in imitation of the
sound. In all times of the day, where this animal is abundant, the
noise may be heard, and sometimes directly beneath one's feet. When
kept in a room, the Tucutucos move both slowly and clumsily, which
appears owing to the outward action of their hind legs; and they are
likewise quite incapable of jumping even the smallest vertical height.
Mr. Reid, who dissected a specimen which I brought home in spirits,
informs me that the socket of the thigh-bone is not attached by a
ligamentum teres; and this explains, in a satisfactory manner, the
awkward movements of their hinder extremities. Their teeth are of a
bright wax yellow, and are never covered by the lips: they are not
adapted to gnaw holes or cut wood. When eating any thing, for instance
biscuit, they rested on their hind legs and held the piece in their
fore paws; they appeared also to wish to drag it into some corner.
They were very stupid in making any attempt to escape; when angry or
frightened, they uttered

the Tucutuco. Of those I kept alive,
several, even the first day, were quite tame, not attempting to bite or
to run away; others were a little wilder. The man who
caught them asserted that very many are invariably found blind. A
specimen which I preserved in spirits was in this state; Mr. Reid
considers it to be the effect of inflammation in the nictitating
membrane. When the animal was alive, I placed my finger within half an
inch of its head, but not the slightest notice was taken of it: it
made its way, however, about the room nearly as well as the others.
Considering the subterranean habits of the Tucutuco, the blindness,
though so frequent, cannot be a very serious evil; yet it appears
strange that any animal should possess an organ constantly subject to
injury. The mole, whose habits in nearly every respect, excepting in
the kind of food, are so similar, has an extremely small and protected
eye, which, although possessing a limited vision, at once seems adapted
to its manner of life.

"Several species probably will be
found to exist south of the Plata. At Bahia Blanca (Lat. 39°) an
animal
burrows under ground in the same manner as the C. Braziliensis,
and
its noise is of the same general character, but instead of being double
and repeated twice at short intervals, it is single and is uttered
either at equal intervals, or in an accelerating order. I was
assured by the inhabitants that these animals are of various colours,
and, therefore, I presume that the two kinds of noises proceeded from
two species. However this may be, they are extraordinarily numerous:
many square leagues of country between the Sierras Ventana and
Guetru-heigue are so completely undermined by their burrows, that
horses in passing over the plain, sink, almost every step, fetlock
deep. At the Rio Negro (Lat. 41°) some closely allied (or same?)
species utters a noise, which is repeated only twice, instead of three
or four times as with the La Plata kind. The sound is, moreover, louder
and more sonorous; and so closely resembles that made in cutting down
a small tree with an axe, that I have occasionally remained in doubt
for some time to which cause to attribute it. Where the plains of
Patagonia are very gravelly (as at Port Desire and St. Julian) the
Ctenomys, I believe, does not occur; but at Cape Negro, in the Strait
of Magellan, where the soil is damper and more sandy, the whole plain
is studded with the little hillocks, thrown up by this destructive
animal. It occurs likewise south of the Strait, on the eastern side of
Tierra del Fuego, where the land is level. Captain King brought home a
specimen from the northern side of the Strait, which Mr. Bennett* has
called C. Magellanicus: it
is of a different colour from the C.
Braziliensis. I unfortunately did not make any note regarding
the noise
of this southern species: but the circumstance of its existence rather
corroborates my belief in there being several other kinds in the
neighbourhood of the Rio

Negro and Bahia Blanca. Otherwise we
must believe that the same animal utters different kinds of noises, in
different districts; a fact which I should feel much inclined to doubt.

"Azara* says that the Tucutuco may be 'found every where;
provided that the soil be pure sand, and the
situation not subject to be overflowed. As these conditions are
fulfilled only in certain spots, their warrens are far separated from
each other, even sometimes more than twenty-five leagues, without it
being possible to conceive how these animals have been able to pass
from one place to another.' The difficulty, I think, is much
overstated; for, as I have said, the burrows of the Tucutuco are
sometimes made
in very damp places, near lakes; so that they certainly might pass
over almost any kind of country. But if the C. Braziliensis
and C.
Magellanicus be considered as one species, as some French
authors are
inclined to do, then the difficulty will be increased in a very
remarkable manner, as we shall be obliged to transport the Tucutuco
over wide plains of shingle, and across many great rivers, and an arm
of the sea."—D.

"This animal is generally scarce, but
in certain districts, I believe, of an alpine character, it is
abundant. It excavates very extensive superficial burrows, no doubt,
for the purpose of feeding on the roots of plants, as in the case of
the Ctenomys Braziliensis,
the habits of which have just been
described. Horses passing over districts frequented by these animals,
sink fetlock deep through the turf. I procured my specimen from
Valparaiso, where the country-people called it 'Cururo.' "—D.

OCTODON CUMINGII.

Octodon Cumingii, Bennett,
Proc. of
Committee of Science and Correspondence of the Zool. Soc. for 1832, p.
46.

These little animals are exceedingly
numerous in the central parts of Chile. They frequent by hundreds the
hedge-rows and thickets, where they make burrows close together,
leading one into another. They feed by day in a fearless manner; and
are very destructive to fields of young corn; when disturbed, they all
run together towards their burrows in the same manner that rabbits in
England do when feeding outside a covert. When running they carry their
tails high up, more like squirrels than rats; and they often remain
seated on their haunches, like the former animals. According to Molina*
they lay up a store of food for the winter, but do not become dormant.
The Octodon is the "degu" of that author: he says that the Indians in
past times used to eat them with much relish. These animals appear to
be very subject to be piebald and albinos; as if partly under the
influence of domestication.

The genus Abrocoma is
evidently allied
on the one hand to the genera Octodon,
Poephagomys, and Ctenomys, and
on the other to the family Chinchillidæ.
The four genera just
mentioned possess so many characters in common, that it would be well
to unite them, and the name Octodontidæ
may be used to designate the
group.

The Octodontidæ appear to
bear the
same relations to Echimys, as
the Arvicolæ do to the Muridæ.

In the Octodontidæ the
skull is rather
short, the inter-orbital space is broad; the ant-orbital passage is
large; the zygomatic arch is thrown out horizontally from the plane of
the palate; the malar bone is broad and somewhat compressed, and
throws up a small post-orbital process; the glenoid cavity of the
temporal bone is narrow; the palate is contracted, and deeply notched
posteriorly, the portion which lies between the molar teeth descends
below the level of the anterior portion; the incisive foramina are
wide: the body of the anterior and posterior sphenoids is very narrow,
and the foramina on either side of them are large: the occipital
condyles are very narrow, widely separated, and the articular surface
is nearly vertical.* The descending ramus
of the lower jaw springs from
the outer side of the alveolar portion, and terminates in a point, more
or less acute.

The incisors of the upper and lower
jaws are of the same width: the molars are 4-4/4-4, rootless.

In external characters the species of
the present group vary considerably. The toes are 5 / 5
or 4 / 5. The
claws
of the hind feet are covered by strong, curved bristly hairs.

The principal points of distinction in
the external characters of the four genera under consideration, may be
thus expressed.

†
TOES 5 /
5.

A. Fore feet formed
for
burrowing—strong and armed with large claws; tail short.

a.
Ears minute,
incisors
very broad
. . . . . . .

Ctenomys.

b.
Ears small, incisors
broad . . . . .
. . . .

Poephagomys.

B. Fore feet weak;
claws
small;
incisors narrow; ears large.

a.
Tail with the apical
portion
furnished with long hair . , . .

Octodon.

†
† TOES 4
/ 5.

b.
Tail furnished
throughout with short
adpressed hairs . . . .

Abrocoma.

It is not only in the comparatively
small size and weakness of the fore feet that Abrocoma
approaches more
nearly to Octodon; but it
agrees in having the soles, both of the fore
and hind feet (which are devoid of hair), covered with minute round
fleshy tubercles (see the under side of the tarsus figured in Plate
28.)

In Octodon, however, the
toes have on
their under side transverse incisions, as the Muridæ, and
many other
Rodents; a character not found in Abrocoma.

* There is a wide difference between
the present animals and the Arvicolidæ
in the form of the occipital
condyles: the same difference is also observable between Echimys
and
Mus. The Octodontidæ in fact have the same
form of condyles as the
Chinchillas and Cavies. In this and many other characters the last
mentioned animals evince an affinity to the Leporidæ.

Here the under-side of the toes, like
the sole of the foot, is covered with minute tubercles.

Though in the form of the skull
Abrocoma Cuvieri* agrees most
nearly with that of Octodon; it differs
in having the anterior portion narrower and rather larger, compared to
the part devoted to the protection of the brain; the zygomatic arch is
shorter, the incisive foramina are longer, the body of the anterior
sphenoid is narrower, and the auditory bullæ are larger. The principal
differences observable in the form of the lower jaw of Abrocoma,
when
compared with that of Octodon,
consists in the coronoid process being
smaller, the condyloid narrower from front to back; the descending
ramus more deeply emarginated
posteriorly, and the angle longer and
more attenuated.

In those characters in which the skull
of Abrocoma departs from that
of Octodon, it approaches
nearer to
Chinchilla. In the peculiar
form and large size of the ears, in the
extreme softness of the fur, in the greater development of the pads on
the under side of the toes, and in the possession of only four toes to
the fore feet, there are other points of resemblance between Abrocoma
and Chinchilla. In the
Chinchilla as well as in Octodon
and Abrocoma,
we find the toe corresponding to the second (counting from the inner
side) furnished with a broad hollow nail;† there are also stiff
bristly hairs covering this nail as in the Octodontidæ.

The extreme softness of the fur of the
animals about to be described, suggested for them the generic name of
Abrocoma. The fur consists of
hairs of two lengths, and the longer
hairs are so extremely slender that they might almost be compared to
the web of the spider. The specific names applied are those of the
distinguished naturalists who first made us acquainted with the two
genera, Octodon and Poephagomys.

1. ABROCOMA BENNETTII.

PLATE XVIII.

Abrocoma Bennettii,
Waterh., Proceedings of the
Zoological Society of London, for February
1837, p. 31.

feet rather small, tarsus short; tail
rather shorter than the body, thick at the base; fur long and
extremely soft, and silk-like. General colour pale grayish brown, with
a slight yellow wash; the upper part of the head and the back dusky
brown; under parts of the body very pale yellowish brown, inclining to
white; chin and throat whitish; feet dirty white; tail well clothed
with hairs, which are closely adpressed, brown above, and of a very
pale brown beneath at the base, darker towards the apex. The hairs of
the moustaches are numerous, long, rather slender, and of a brownish
colour. The ears are brown, furnished externally at the base with fur
resembling that of the body; the remaining parts (both external and
internal) are beset with long and extremely slender brown hairs, which
project considerably beyond the margin of the ear. The ordinary fur on
the back is about ten lines in length, but thickly interspersed with
this fur, are longer hairs which are so delicate that they may almost
be compared to the spiders' thread. Both on the upper and under side of
the body the fur is deep gray at the base. The incisors are yellow.

In.

Lines.

In.

Lines.

Length

from nose to root of tail . .

9

9

Length of tarsus (claws
included) . .

1

4

of tail . . . .
. .

5

0

of ear . . . . .

0

10

from nose to ear . .

1

11

Width of ear . . . . .

1

0½

Habitat, Chile, (August.)

"This animal was caught amongst some
thickets in a valley on the flanks of the Cordillera, near Aconcagua.
On the elevated plain, near the town of Santa Rosa, in front of the
same part of the Andes, I saw two others, which were crawling up an
acacia tree, with so much facility, that this practice must be, I
should think, habitual with them."—D.

2. ABROCOMA CUVIERI.

PLATE XXIX.

Abrocoma Cuvieri, Waterh.,
Proceedings
of the Zoological Society of London for February 1837, p. 32.

soft; general colour gray faintly
washed with yellow; under parts of the body grayish white; feet dirty
white; tail dusky, paler beneath at the base: the ears are large,
distinctly emarginated behind, and appear to be almost naked, but, upon
close examination, long and extremely fine hairs may be observed. All
the fur is gray at the base; the hairs of the moustaches are numerous
and very long, those nearest the mouth are white, the others are black
at the base and grayish beyond. The incisors are of a palish yellow
colour.

In.

Lines.

In.

Lines.

Length

from nose to root of tail . .

6

6

Length of tarsi (claws
included) . .

1

1

of tail . . . .
. .

2

10

of ear . . . . .

0

7

from nose to ear . .

1

4

Width of ear . . . . .

0

7½

Habitat, Chile, (September.)

This species is about one-third the
size of the last, it differs moreover in being gray instead of brown,
and in having the posterior margin of the ear emarginated; the tail is
also rather shorter in proportion.

The skull * is figured in Plate 33, fig.
1, a, and 1, b; and fig. 23, a, Plate
34. Its length is 1 inch,
4½
lines; width 9¼ lines; length of nasal bones 6 lines; distance
between fore part of incisors and the front molar (upper jaw) 5 lines;
longitudinal extent of the three molars of upper jaw 3 lines; length
of auditory bullæ 5¾ lines; length of ramus of lower jaw
(see Plate
33, fig. 1, c,), without
incisors, 11½ lines. Fig. 23, c,
Plate 34,
represents the inner side of a ramus
of the lower jaw: fig. 1, d,
Plate 33, is the lower jaw seen from above: fig. 23, b,
Plate 34, is
the same seen from beneath. This view is given to show the position of
the descending ramus of the lower jaw—that it springs from the outer
side of the alveolar portion, as in a great portion of the South
American Rodents, such as Dasyprocta,
Myopotamus, Echimys, Chinchilla,
and also in that genus found in the West Indian islands, Capromys.
Fig.
1, e, Plate 33, represents
the molar teeth of the upper jaw, and fig. 1, f, those of the
lower.

"This species is abundant on the dry
hills, partly covered with bushes, near Valparaiso."—D.

* The skull is, unfortunately,
imperfect, the hinder portion is injured, and the arches which enclosed
the ant-orbital openings are broken.

"I will not repeat what I have said
about the habits of this animal in my Journal, as it is merely a
corroboration of Azara's account. According to that author, the
Bizcacha is not found north of 30°; and its southern limit occurs in
the neighbourhood of the Rio Negro in 41°. Where the plains are
gravelly, it is not abundant, but (differently from the Cavia
Patagonica,) it prefers an argillaceous and sandy
formation,
such as
that near Buenos Ayres. The Bizcacha abounds over the whole Pampas,
even to the neighbourhood of Mendoza, and there it is replaced in the
Cordillera by an Alpine species. Of the latter animal, I saw one seated
on a pinnacle at a great height, but I could not obtain a specimen of
it. Azara* has remarked that the Bizcacha, fortunately for the
inhabitants of Banda Oriental, is not found to the eastward of the Rio
Uruguay; and what makes the case more remarkable is, that although
thus bounded by one river, it has crossed the broader barrier of the
Parana, and is numerous in the province of Entre Rios. I was assured by
a man, whose veracity I can perfectly trust, that these animals, quasi
canes, post coitum adnexi sunt."—D.

FAMILY—CAVIIDÆ.

KERODON KINGII.

Kerodon Kingii, Bennett,
Proceedings of
the Zoological Society of London for 1835, p. 190.

Habitat, Patagonia.

"The Kerodon is common at intervals
along the coast of Patagonia, from the

Rio Negro (Lat. 41°) to the Strait of
Magellan. It is very tame, and commonly feeds by day: it is said to
bring forth two young ones at a birth. At the Rio Negro it frequents in
great numbers the bottoms of old hedges: at Port Desire it lives
beneath the ruins of the old Spanish buildings. One old male killed
there weighed 3530 grains. At the Strait of Magellan, I have seen
amongst the Patagonian Indians, cloaks for small children made with
the skins of this little animal; and the Jesuit Falkner says, that the
people of one of the southern tribes, take their name from the number
of these animals which inhabit their country. The Spaniards and
half-civilized Indians, call the Kerodon, 'conejos,' or rabbit; and
thus the mistake has arisen, that rabbits are found in the
neighbourhood of the Strait of Magellan."—D.

1. CAVIA COBAIA.

Cavia Cobaia, Auct.

Habitat, Maldonado, La Plata, (June.)

"This animal, known by the name of
Aperea, is exceedingly common in the neighbourhood of the several towns
which stand on the banks of the Rio Plata. It frequents different kinds
of stations,—such as hedge-rows made of the Agave and Opuntia, or
sand-hillocks, or again, marshy places covered with aquatic plants;—the
latter appearing to be its favourite haunt. Where the soil is
dry, it makes a burrow; but where otherwise, it lives concealed amidst
the herbage. These animals generally come out to feed in the evening,
and are then tame; but if the day be gloomy, they make their
appearance in the morning. They are said to be very injurious to young
trees. An old male killed at Maldonado, weighed 1 lb. 3 oz. In all the
specimens I saw there, (during June, or winter,) I observed, that the
hair was attached to the skin less firmly than in any other animal I
remember to have seen."—D.

"This animal is found only where the
country has rather a desert character. It is a common feature in the
landscape of Patagonia, to see in the distance two or three of these
Cavies hopping one after another in a straight line over the gravelly
plains, thinly clothed by a few thorny bushes and a withered herbage.
Near the coast of the Atlantic, the northern limit of this species is
formed by the Sierra Tapalguen, in latitude 37° 30', where the plains
rather suddenly become greener and more humid. The limit certainly
depends on this change, since near Mendoza, (33° 30'.) four degrees
further northward, where the country is very sterile, this animal again
occurs. Azara erroneously supposed that its northern range was only
35°. * It is not clear on what circumstances its limit southward
between Ports Desire and St. Julian (about 48° 30'.) depends; for
there is in that part no change in the features of the country. It is,
moreover, a singular circumstance, that although the Cavy was not seen
at Port St. Julian during our voyage, yet Capt. Wood, in 1670, speaks
of them as being numerous there. What cause can have altered, in a
wide, uninhabited, and rarely visited country, the range of an animal
like this ?

"Azara states,† that the Cavy never
excavates its own burrow, but uses that of the Bizcacha. Wherever this
animal is present, without doubt this is true; but on the sandy plains
of Bahia Blanca, where the Bizcacha is not found, the Spaniards
maintain that the Cavy is its own workman. The same thing occurs with
the little owls of the Pampas (Noctua
cunicularia), which have been
described by travellers as standing like sentinels at the mouths of
almost every burrow; for in Banda Oriental, owing to the absence of
the Bizcacha, these birds are obliged to hollow out their own
habitations. Azara says, also, that this Cavy, except when pressed by
danger, does not enter its burrow; on this point I must again differ
from that high authority. At Bahia Blanca I have repeatedly seen two or
three of these animals sitting on their haunches by the mouths of their
holes, which they quietly entered as I passed by at a distance. Daily,
in the neighbourhood of these spots, the Cavies were abundant: but
differently from most burrowing animals, they wander, commonly two or
three together, to miles or leagues from their home; nor do I know
whether they return at night. The Cavy feeds and roams about by day;
is shy and watchful; seldom squats after the manner of a hare; cannot
run very fast, and, therefore, is frequently caught by a couple of
dogs, even of mixed breed. Its manner of running more resembles that of
a rabbit than of a hare. The Cavy generally produces two young ones at
a birth, which are brought forth within the burrow. The flesh, when
cooked, is

very white; it is, however, rather
tasteless and dry. Full grown animals weigh between twenty and
twenty-six pounds.'—D.

HYDROCHŒRUS CAPYBARA.

Hydrochœrus Capybara, Auct.

"These animals are common wherever
there are large rivers or lakes, over that part of the South American
Continent which lies between the Orinoco and the Plata, a distance of
nearly 1400 miles. They are not generally supposed to extend south of
the Plata; but as there is a Laguna Carpincho (the latter being the
provincial name of the Capybara) high up the Salado, I presume they
have sometimes been seen there. Azara does not believe they ever
frequent salt water; but I shot one in the Bay of Monte Video; and
several were seen by the officers of the Beagle on the Island of
Guritti, off Maldonado, where the water is very nearly as salt as in
the sea. The one I shot, at Monte Video, was an old female; it
measured
from tip of snout to end of stump-like tail, 3 feet 8½ inches, and in
girth 3 feet 2 inches. She weighed 98 pounds. I opened the stomachs of
a couple, which I killed near a lake at Maldonado, and found them
distended with a thin yellowish-green fluid, in which not more than a
trace of a vegetable fibre could be distinguished: it is in accordance
with this fact, that a part of the æsophagus is so narrow, as I am
informed by Mr. Owen, that scarcely anything larger than a crow-quill
can be passed down it. The shape of the dung of these animals is a
short straight cylinder, rounded at the extremities; when dried and
burnt, it affords a pleasant smell like that from cedar wood. These
animals do not burrow holes, but live amongst the thickets, or beds of
rushes near rivers and lakes. At Maldonado they often may be seen
during the day, seated on the grassy plain in small groups of three and
four, at the distance of a few yards from the border of the lake, which
they frequent. I must refer the reader for a few more details
respecting their habits, to my Journal of Researches.—D."

"A black variety of the domesticated
species, which was turned out on these islands by the earlier
colonists, has been considered, but with some hesitation, by M. Lesson,
as a distinct species. He has called it Lepus Magellanicus,
and has
given the following specific character, — 'Pilis omnino
atro-violaceis, albis passim sparsis: auriculis fuscis, capite
brevioribus; maculâ albâ naso,
interstitio narium, menti, gulæ,
frontique.' * In the specimens preserved on board the Beagle,
the form
and position of the white marks neither agree with M. Lesson's
description, nor with each other. In one there is a broad white patch
on one side of the head, and another on one of the hinder thighs. The
Spaniards employed in hunting wild cattle, (who are all excellent
practical observers) assured me, that the black rabbits were only
varieties of the common gray kind, and they gave the following reasons
for thinking so;—namely, that the two sorts did not live apart; that
the black one had not a different range from the other; that the two
bred freely together, and that they produced pie-bald offspring. As the
rabbits extend their range very slowly, (not having yet crossed the
central range,) the Spaniards have sometimes carried a few aud turned
them out in different parts of the island, and thus they have
ascertained that the black and gray kinds breed together freely.
Bougainville, moreover, who visited the part of the island, where the
black variety is now most common, distinctly states, in his voyage
round the world, that no animal, excepting the great wolf-like fox
inhabited these islands. M. Lesson supposes that the Lepus
Magellanicus
is found near the Strait of Magellan; but I inquired of the Indians,
who live there, and they knew of no other 'conejos' or rabbits,
except
the Kerodon Kingii, which no
doubt is the animal alluded to by the
early voyagers."—D.

1. DASYPUS HYBRIDUS.

Dasypus hybridus, Auct.

"This species seems to prefer rocky
and slightly undulating ground, and

hence is common in Banda Oriental and
Entre Rios. Azara says it is found from 26° 30', to at least 41° south;
but, I was assured, perhaps incorrectly, that the Sierra Tapalguen
(37° 30'), where the nature of the country becomes slightly different,
is its southern limit. The D.
villosus, minutus, and
mataco, are found
at Bahia Blanca, in latitude 39°. I was also assured that these three
species, together with the D.
hybridus, frequent the plains near
Mendoza, in latitude 33° to 34°."—D.

2. DASYPUS MINUTUS.

Dasypus minutus, Auct.

"The northern limit of this species on
the Atlantic side of the continent, is (as I was told by the
inhabitants) near the southern one of the D. hybridus,
namely, 37° 30'.
It is extremely abundant on the arid plains near the Sierra Ventana,
and likewise in the neighbourhood of the Rio Negro. This species has a
range considerably further southward than any other: I obtained
specimens at Port Desire, where, however, it is far from common, and at
Santa Cruz (in latitude 50°) I saw its tesselated covering lying on the
ground. At Bahia Blanca, I found in the stomach of this armadillo,
coleoptera, larvæ, roots of plants, and even a small snake of the
genus Amphisbæna. All the species, excepting one, wander about by day.
At Bahia Blanca, during a morning's ride, three or four of the D.
minutus generally were met with; but, in order to secure them,
it was
necessary to jump off one's horse as quickly as possible, otherwise,
they would have disappeared by burrowing in the sandy soil. This
species often endeavours to escape detection by squatting close to the
ground, and remaining motionless."—D.

1. DIDELPHIS AZARÆ.

Didelphis Azaræ, Auct.

"This species is said to inhabit
burrows: it is nocturnal, and is very destructive to poultry. The body
after death possesses a very offensive odour. My specimen was procured
at Maldonado."—D.

DESCRIPTION. — Head short; ears small,
the posterior edge emarginated near the base, distinctly furnished with
hairs; tail slightly exceeding the body in length, very thick at the
base; tarsi small; fur moderately long, slightly harsh, and somewhat
adpressed (much less woolly than in most Opossums): general tint
brownish yellow, under parts paler; anterior angle of the eye and
muzzle brown, the tip of the chin, and also the tip of the muzzle on
either side whitish; on the cheeks, a little below the eyes, is a
patch of yellow which extends round the angle of the mouth: about
one-third of the tail is covered with fur of the same colour and
character as that on the body; beyond this the tail is black,
excepting a small portion, about one inch in length, at the apex, which
is white; and the hairs are short, closely adpressed, and scarcely
hide the scales which are beneath: the fore portion of each foot is
brown: the hairs covering the ears on the outer side are brownish, and
those on the inner side of the ear are yellow, but towards the outer
margin they are brown. The hairs of the back have the basal half gray,
and the apical half ochreous, terminating in yellowish brown; on the
belly and underside of neck, the hairs are ochreous, faintly tinted
with gray at the base.

In.

Lines.

In.

Lines.

Length

from nose to root of tail . .

1

3

Length of tarsus . . . . .

1

5½

of tail . . . .
. .

10

3

of ear . . . . .

0

6

from nose to ear . .

2

1½

Habitat, Maldonado, La Plata, (June).

The species described by Azara, under
the name Macrouré à grosse queue,
agrees so perfectly with the present
animal, that I have no hesitation in referring

it to the Didelphis crassicaudata
of
Desmarest, which is founded upon Azara's description.

The head of the Didelphis
crassicaudata
is shorter and less pointed than in most other Opossums; the ears are
unusually small, and the tail is very thick. In the character of the
fur also, this species differs from most others, the hairs being rather
short and somewhat adpressed; and the soft under-fur being very
scanty. Upon separating the fur on the back and sides of the body,
numerous young hairs were visible in the specimen from which the above
description is taken, and these were of a bright rusty red tint; the
colouring of the animal therefore would, in all probability, have been
very different after a short time, had it not been killed. Those
observed by Azara varied considerably in their colouring. The skull is
figured in Plate 34. figs. 25. Fig. d
represents a ramus of the
lower
jaw.

DESCRIPTION.—Muzzle slender and pointed; ears large; tail rather
shorter than the head and body taken
together; fur long and very soft: general tint of the upper parts of
the head
and body ashy-gray washed with brown; on the sides of the body,
especially near the shoulders, a faint yellowish tint is observable;
the lower part of the cheeks, the throat, under parts of the body and
the feet, are white, with an indistinct yellowish tint; the eyes are
encircled with brownish-black, which tint is extended forwards on to
the sides of the muzzle; the upper surface of the muzzle and the
inter-orbital space is

pale. The tail is furnished throughout
with minute decumbent hairs, excepting a small naked space at the tip
beneath, of about one line in length; on the upper surface they are
brown, and on the under, they are whitish. The fur of the upper and
under parts of the body is deep gray at the base; on the lower part of
the cheeks, chin, and on the mesial line of the throat and chest, the
hairs are uniform—not gray at the base. The ears are brown, and to the
naked eye, appear naked.

In.

Lines.

In.

Lines.

Length

from nose to root of tail . .

4

6

Length from nose to ear . . .

1

1½

of tail . . . .
. .

4

4

of ear . . . . .

0

7¼

of tarsus (claws included) .
.

0

7½

width
of ear . . . .

0

7½

Habitat, Valparaiso, Chile, (October.)

This little Opossum, which is the only
species I am acquainted with from the west side of the Cordillera, was
exhibited at one of the scientific meetings of the Zoological Society,
and its characters were pointed out by Mr. James Reid, who proposed for
it the specific name of hortensis,*
a name which was given from the
circumstance that in Mr. Darwin's notes it is stated that a small
Opossum was found in a garden at Maldonado. These notes however refer
to the Didelphis brachyura.
The skull of this animal is figured in
Plate 35. Fig. 5, a,
represents the upper side; 5, b,
the under side;
and 5, c, is the side view.
Fig. 5, d, is the lower jaw,
and 5, e, is
the same magnified. The length of the skull is 14½ lines; width, 8
lines; length of palate, 7¼ lines; inter-orbital space, 2½ lines;
length of ramus of lower jaw,
10½ lines. In the palate are two long
openings which commence opposite the posterior false molar, and
terminate opposite the hinder portion of the penultimate true molar:
the incisive foramina are nearly one line in length. On the posterior
portion of the palate there are four other foramina, one on each side
near the posterior molar, and one on either side the mesial line,
behind the large palatine openings above mentioned.

"These little animals frequent the
thickets growing on the rocky hills, near Valparaiso. They are
exceedingly numerous, and are easily caught in traps baited either with
cheese or meat. The tail appeared to be scarcely at all used as a
prehensile organ; they are able to run up trees, with some degree of
facility. I could distinguish in their stomachs the larvæ of
beetles."—D.

* See Proceedings of the Zoological
Society of London for January, 1837, p. 4.; its characters were not
published.

DESCRIPTION.—Head large; canine teeth
very large; ears rather small; tail short, rather more than half the
length of the body; fur short and crisp; the back and upper surface
of the head ashy gray, grizzled with yellowish white; the sides of the
head and body, and under parts rusty yellow, rather paler on the belly
than on other parts, and of a deeper hue on the rump and cheeks; the
eye is encircled with rusty yellow; feet yellowish; tail clothed with
short stiff hairs, and exhibiting scales, brownish above, and dirty
yellowish white beneath—a small naked space beneath, at the tip, of
about two lines in length. Fur of the back grayish at the base, that on
the belly uniform; ears clothed with minute yellowish white hairs.

In.

Lines.

In.

Lines.

Length

from nose to the root of tail
. .

6

0

Length of tarsus (claws
included) . .

0

8¾

from
nose to ears . . .

1

6

of ear . . . . .

0

3¾

of tail . . . . .

2

8

Habitat, Maldonado, La Plata, (June.)

Never having seen a good figure of this
animal, I have thought it desirable to introduce it in the plates of
this work.

The Didelphis brachyura is
closely
allied to the D. tricolor of
authors, but in that species the upper
parts of the body are nearly black; the sides of the head and body are
of a deep rusty red tint, and the under parts are almost white.

"Was caught by some boys digging in a
garden. Its intestines were full of the remains of insects, chiefly
ants and others of the Hemipterous order."—D.